Stutter rough idle when first starting car and clears up after 3-4 seconds.

[NitroViper]

My car has done this even before the rebuild so I am not sure whats up with it.
The engine stutters for a few seconds and then smooths out by itself and runs fine after.
Has new pistons, rings, rods, injectors, plugs, bosch red top coils, no carbon in the engine, timing chains and tensioners, charcoal filter, basically most things in the engine are brand new yet it is still doing it. I mean It does it maybe once out of every 10 starts but makes no sense to me.

**EDIT**
To save you guys some reading a new black top PCV fixed my issue.
When my car was having oil consumption issues I purchased an updated white top PCV to see if it would help. I did NOT have my ECU flashed to go with it. I didnt give it a second thought because this was soon after I bought the car.
After pages and pages and testing in the post it became clear it was probably a vacuum difference between PCV's. Anyways, I purchased a $16 PCV from ebay to test it and its fixed...

[Benji16]

Mine does the same thing. very annoying is like a misfire at start up right? it stutters and rpms fluctuate? then after a little bit it will smooth out? have you tried when it does that hit the gas peddle a little then it goes away?

[Spawne32]

How old is your HPFP?

[NitroViper]

How old is your HPFP?

Probably stock. Maybe I should replace it before I upgrade the Turbo. The plunger had no wear tho when I looked at it.

[Spawne32]

Probably stock. Maybe I should replace it before I upgrade the Turbo. The plunger had no wear tho when I looked at it.

How many miles though? Typically after 100k they start showing signs of being worn out by having low fuel pressure on a cold start. You can pick up a new hitachi unit off rockauto.

[NitroViper]

Dang those basitges arent cheap lol.

81k right now.

[Spawne32]

HITACHI HPP0010 should be about $215 bucks

[NitroViper]

Cant tell if it comes with the cam follower.
It's more on FCP but lifetime warranty. But still cant tell if it comes with the cam follower.
https://www.fcpeuro.com/products/audi-mechanical-fuel-pump-06j127025j

[Spawne32]

You won't need a new cam follower, its a roller follower, I have never ever seen one worn out.

[Traptalk]

You can’t run an upgraded hpfp without software for it, just so ya know. Not needed for k04 on 93

[NitroViper]

You can’t run an upgraded hpfp without software for it, just so ya know. Not needed for k04 on 93

The HIT-HPP0010 is an upgraded fuel pump?

[Spawne32]

You can’t run an upgraded hpfp without software for it, just so ya know. Not needed for k04 on 93

Who said any thing about an upgraded hpfp?

[Spawne32]

The HIT-HPP0010 is an upgraded fuel pump?

That's the OE replacement part number, i can point to it on my car if you want. :p

[Traptalk]

I misread. Disregard.

[NitroViper]

That's the OE replacement part number, i can point to it on my car if you want. :p

Lol I took mine off... I know where it is.

[FLProdigy]

Mine does same thing. Read about HPFP being possible issue.

One member replaced throttle body and it didnt seem to help.

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[RPMtech147]

Have you watched misfires/Fuel pressure on VCDS during cold start? Are you using OE plugs?

[Traptalk]

I just picked up that hitachi pump since mine had 140k on it. On rock auto it’s like 225 plus shipping and tax

[NitroViper]

Have you watched misfires/Fuel pressure on VCDS during cold start? Are you using OE plugs?

I dont have VCDS but I do have obdeleven tho. I havent messed with it yet.

[Spawne32]

OBDeleven will do live data as well.

[Benji16]

where do i go on live data to check cold start fuel pressure?
OBDeleven will do live data as well.

[Spawne32]

where do i go on live data to check cold start fuel pressure?

When you go into the engine module, there should be two options for live data and charts, then you will select something with fuel rail pressure, i forget what the channel name is called.

[NitroViper]

We need a dedicated OBDeleven thread with whats what on that thing.

[Benji16]

Thats what i needed to know the channel lol
When you go into the engine module, there should be two options for live data and charts, then you will select something with fuel rail pressure, i forget what the channel name is called.

[Benji16]

Dude if you end up replacing your HPFP and the problems stop let me know i have the same issue but not all the time.
We need a dedicated OBDeleven thread with whats what on that thing.

[NitroViper]

Dude if you end up replacing your HPFP and the problems stop let me know i have the same issue but not all the time.

It's random, I probably wont buy one untill its happening all the time. I got enough money in this car at the moment.

[Theiceman]

do you hear the fuel pump prime when you open the drivers door ?

[NitroViper]

do you hear the fuel pump prime when you open the drivers door ?

Ive heard it yes but never paid attention to listen for it every single time.

[Theiceman]

just thinking maybe the pump wasnt priming.. that would explain a stumble at the start then recovering.

[NitroViper]

just thinking maybe the pump wasnt priming.. that would explain a stumble at the start then recovering.

I actually listening for it today before I started it, I heard and then proceeded to start it for the first time today. It messed up for a few seconds and was normal. I guess I should figure out this OBDeleven and tho I have no idea what I am looking for in it. And itl be hard to catch since its random. Im sure its misfiring on startup but have no idea what the fuel pressure should be.

[Benji16]

i have new PCV, carbon cleaned, new bosch ignition coils, ngk spark plugs and still misfires on startup but not all the time either has has 100k. I'm thinking my HPFP is getting weaker and not providing enough fuel on start up or my LPFP is weak? can i check duty cyle on this pump like in the B7's?

[dalmation53]

[emoji848][emoji848][emoji848] I have the same problem....what the hell? I really can't figure it out either [emoji30]

[markcm]

+1

My 2010 2.0T idles rough on cold start too. Runs great otherwise, gets 30-34mpg on the highway which is nice but the rough start is a bit annoying.

[NitroViper]

So all of us that has this problem no one tried a new fuel pump?

[JLAllroad]

One test, after driving (engine hot) take note of the hpfp pressure at idle, turn engine off, over the course of 5 minutes the pressure should build to 2-3xs idle pressure, if it doesn’t, or it drops, its either an injector (if fuel in oil) or the hpfp is on its way out.


Sent from my iPhone using Audizine (http://r.tapatalk.com/byo?rid=87676)

[Novarider]

Leaking HPFP would be my guess without further tests. Does your oil smell like gas?

IMO the HPFP should be a maintenance item that's changed at 100k or sooner if needed.

[dalmation53]

Why don't you change it and update us lol.
So all of us that has this problem no one tried a new fuel pump?

[dalmation53]

Bro same here. i get like 34mpg and it rides beautiful all the time. it's just that rough start. i might do a test with my dads HPFP from his B8.5 to see if his car does it with my hpfp on his car.
+1

My 2010 2.0T idles rough on cold start too. Runs great otherwise, gets 30-34mpg on the highway which is nice but the rough start is a bit annoying.

[bb-tt]

Bro same here. i get like 34mpg and it rides beautiful all the time. it's just that rough start. i might do a test with my dads HPFP from his B8.5 to see if his car does it with my hpfp on his car.

Reallly???? How many miles do you get to a tank and how many gallons do you put in when you fill up?

[JLAllroad]

Reallly???? How many miles do you get to a tank and how many gallons do you put in when you fill up?

I CAN get 31-33 all highway, probably even a bit more if I keep it at 70mph, but 28-29 is typical set to cruise in Mexico @82mph with plenty of WOT passing.

Real world mixed is 21-22, 3-4 less on straight E85.

Love 350lbs+ of torque but it’s necessary in the 4000lb wagon.


Sent from my iPhone using Audizine (http://r.tapatalk.com/byo?rid=87676)

[NitroViper]

So no one has ever fixed this problem we can just guess it might be the HPFP? This car will nickle and dime me to death on guesses.

[Theiceman]

So no one has ever fixed this problem we can just guess it might be the HPFP? This car will nickle and dime me to death on guesses.Depends who's helping you. But yeah some problems are tough..

Sent from my SM-G973W using Audizine mobile app (http://r.tapatalk.com/byo?rid=87676)

[NitroViper]

Depends who's helping you. But yeah some problems are tough..

Sent from my SM-G973W using Audizine mobile app (http://r.tapatalk.com/byo?rid=87676)

Everything is brand new basically, even the turbo. Only things that arent new is the block, water pump, fuel pump, intake/throttle body... It's either in the electronics/ sensor or the Fuel pump itself probably. Maybe I should clean the MAF.

[dalmation53]

I already did that. No change but try it.

[NitroViper]

Ive searched and read so many threads of guys just about changing everything and never found an answer and the thread just dies with no answers. I hate this car, I need answers! lol

[Spawne32]

Depends who's helping you. But yeah some problems are tough..

Sent from my SM-G973W using Audizine mobile app (http://r.tapatalk.com/byo?rid=87676)

The thing about the parts cannon is that sometimes its cheaper than buying the equipment needed to diagnose a car.

[Theiceman]

Ive searched and read so many threads of guys just about changing everything and never found an answer and the thread just dies with no answers. I hate this car, I need answers! lolWelcome, you are truely one of us now
Lol



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[dalmation53]

It seems like this car is stressing you out in life. maybe you should sell it and gain back w.e you fixed on it. then buy a Lexus and never worry about nothing failing. 210k on my mothers is250 has been more reliable then my last EX GF[emoji4]
Ive searched and read so many threads of guys just about changing everything and never found an answer and the thread just dies with no answers. I hate this car, I need answers! lol

[NitroViper]

It seems like this car is stressing you out in life. maybe you should sell it and gain back w.e you fixed on it. then buy a Lexus and never worry about nothing failing. 210k on my mothers is250 has been more reliable then my last EX GF[emoji4]

It's to late to go back now. Soon the car wont even have german parts in it anymore and maybe ill be more reliable.

[Novarider]

It's to late to go back now. Soon the car wont even have german parts in it anymore and maybe ill be more reliable.

No German parts? Are you using cheap Chinese parts for everything? If so, that could be your problem.....

[NitroViper]

No German parts? Are you using cheap Chinese parts for everything? If so, that could be your problem.....

kolbenschmidt, elring, borgwarner, bosch...

[Novarider]

kolbenschmidt, elring, borgwarner, bosch...

You know 3 of those are German, right?

[Benji16]

Those are All OEM parts. The only thing chinese is his K04 turbo. and those seem to be holding up.

[NitroViper]

You know 3 of those are German, right?

Actually each and every one of those companys produce parts outside of Germany, They may originate in Germany but the parts arent produced there.

[NitroViper]

Oh well, ordered the Fuel pump from Rock auto... Hope it fixes the issue. If it doesn't then maybe fuel filter?

[dalmation53]

Oh well, ordered the Fuel pump from Rock auto... Hope it fixes the issue. If it doesn't then maybe fuel filter?

You ordered your HPFP from rock auto?

[NitroViper]

You ordered your HPFP from rock auto?

Yea, pretty sure I just said that haha
HITACHI HPP0010

[Traptalk]

Oh well, ordered the Fuel pump from Rock auto... Hope it fixes the issue. If it doesn't then maybe fuel filter?

More likely the in tank pump then the filter. It’s part of the same assembly so if I was thinking about changing one might as well do the entire assembly

[dalmation53]

I know i wanted to know what brand hitachi is OEM.
Yea, pretty sure I just said that haha
HITACHIHPP0010

[Smac770]

More likely the in tank pump then the filter. It’s part of the same assembly so if I was thinking about changing one might as well do the entire assembly

The B8.0 Bosch pump has a separately replaceable fuel filter. But a new pump includes a new filter.
$62, https://www.genuineaudiparts.com/oem-parts/audi-fuel-filter-8k0201511a
vs
$287, https://www.genuineaudiparts.com/oem-parts/audi-fuel-pump-assembly-8k0919051g
(rev T is for the flex fuel, but we didn't get a B8.0 flex fuel car, so should be irrelevant here)

The B8.5 VDO pump does not have a separately replaceable fuel filter. You want to replace the filter, you have to replace the pump.
$224, https://www.genuineaudiparts.com/oem-parts/audi-fuel-filter-8k0201511ta
(this lacks the fuel level sender, add ~$120 more for a complete unit, which, oddly, varies CAEx vs CPMx, while the pump and filter unit do not)

[Smac770]

I know i wanted to know what brand hitachi is OEM.

I'm not sure I understand what you were trying to say there.

Hitachi is the supplier to Audi of the HPFP used in our engines. You might also see the name as HÜCO (aka Hueco). https://www.hueco.com/dynasite72be.html?dsmid=111335

The HPP0004 is in the B7 "FSI" 2.0T and the HPP0010 is in the B8 "TSI" 2.0T.

[NitroViper]

Having 2 fuel pumps is just dumb... If this doesnt fix it im shipping it back.

[old guy]

I don't know if this helps at all but here it is. This (crappy) video was taken on a cold start 2013 2.0 TFSI. The ambient temperature was 89° f.

What could be noteworthy:

- Prior to ignition the fuel pressure was 362 psi.

- Upon ignition the fuel pressure was 850 psi → 860 psi with fast idle ~1200 rpm

- Timing advance at -17° → -20° ATDC

-Charge voltage ~ 13.5v

-AFR remains around 14.7. O2 equiv. ratio remains at 1.

- At approximately 1 minute the rpm dropped to 750 and the fuel pressure dropped to 560 psi → 570 psi

-Timing advance increased to +3° → +5° BTDC


https://youtu.be/55Ix9IcSzyM

EDIT: Went back and performed a warm start. (No crappy video)

- Fuel pressure at 650 psi

- Upon ignition fuel pressure dropped to 560 psi → 570 psi and remained there.

-Timing advance +3° → +5° BTDC

- No stuttering with either cold or warm start.

[NitroViper]

So on cold start low psi causes stutter? But is it the fuel pump in the gas tank or fuel pump in the engine bay possibly be causing. The last few days its been starting perfectly normal.

[old guy]

So on cold start low psi causes stutter? But is it the fuel pump in the gas tank or fuel pump in the engine bay possibly be causing. The last few days its been starting perfectly normal.

I can't answer that because I do not have any stuttering. You can check your fuel pressure to see if it is significantly lower than mine. If it is you may have your answer.

[NitroViper]

I can't answer that because I do not have any stuttering. You can check your fuel pressure to see if it is significantly lower than mine. If it is you may have your answer.

Is that the torque app? my OBDeleven likes to stop live data for some reason.
So these start fuel pressures are after you hear the fuel pump prime when you open the door?

[old guy]

Is that the torque app? my OBDeleven likes to stop live data for some reason.
So these start fuel pressures are after you hear the fuel pump prime when you open the door?

TorquePro app. Pressures were after opening the door. I heard the pump prime prior to the cold start. I did not hear it when I went back for a warm start. I could have just missed it because it was a little windy.

On the cold start you can see the pressure immediately jump to over 1,000 psi before dropping to 860 psi.

[NitroViper]

Im going to try that, I just went to the store so all I can get is a warm start. But like I said its been normal on cold starts now. Im sure it'll come back. Sometimes its really bad and check engine light comes on for a second and goes out.

[Traptalk]

The B8.0 Bosch pump has a separately replaceable fuel filter. But a new pump includes a new filter.
$62, https://www.genuineaudiparts.com/oem-parts/audi-fuel-filter-8k0201511a
vs
$287, https://www.genuineaudiparts.com/oem-parts/audi-fuel-pump-assembly-8k0919051g
(rev T is for the flex fuel, but we didn't get a B8.0 flex fuel car, so should be irrelevant here)

The B8.5 VDO pump does not have a separately replaceable fuel filter. You want to replace the filter, you have to replace the pump.
$224, https://www.genuineaudiparts.com/oem-parts/audi-fuel-filter-8k0201511ta
(this lacks the fuel level sender, add ~$120 more for a complete unit, which, oddly, varies CAEx vs CPMx, while the pump and filter unit do not)

That’s only one of the fuel filters. How do you replace the inlet pick up screen?

You’d have to disassemble the entire to pump and clean the screen and reuse it to really do it proper

[dalmation53]

get some numbers on fuel pressure psi on cold start and try it on mine and if they match we found the problem.
Is that the torque app? my OBDeleven likes to stop live data for some reason.
So these start fuel pressures are after you hear the fuel pump prime when you open the door?

[NitroViper]

I keep trying to do live data on these numbers but OBDeleven just freezes uo when logging it. Need to try a different android device I guess.

[dalmation53]

did you updated via google play store?
I keep trying to do live data on these numbers but OBDeleven just freezes uo when logging it. Need to try a different android device I guess.

[NitroViper]

did you updated via google play store?

I tried it on my phone and on my RSNAV both freeze

[NitroViper]

This is what my OBDeleven does, I cant even use the chart section on 2 devices.


https://youtu.be/B9U5xfEID6U

[NitroViper]

I don't know if this helps at all but here it is. This (crappy) video was taken on a cold start 2013 2.0 TFSI. The ambient temperature was 89° f.

What could be noteworthy:

- Prior to ignition the fuel pressure was 362 psi.

- Upon ignition the fuel pressure was 850 psi → 860 psi with fast idle ~1200 rpm

- Timing advance at -17° → -20° ATDC

-Charge voltage ~ 13.5v

-AFR remains around 14.7. O2 equiv. ratio remains at 1.

- At approximately 1 minute the rpm dropped to 750 and the fuel pressure dropped to 560 psi → 570 psi

-Timing advance increased to +3° → +5° BTDC


EDIT: Went back and performed a warm start. (No crappy video)

- Fuel pressure at 650 psi

- Upon ignition fuel pressure dropped to 560 psi → 570 psi and remained there.

-Timing advance +3° → +5° BTDC

- No stuttering with either cold or warm start.

OBDeleven seems to be kind of crappy but today I got a cold start reading on fuel pressure at 100psi before starting, the car seemed to start almost normal, may have stuttered for 0.5 seconds. After it started it was around 710psi until it dropped to around 570psi at idle.
I am going to keep trying it until I get the reading before a major stuttering start.

Went out about an hour later after driving it and it was 570psi before start and about 570psi at idle.

If I try to display more than 2 items at once OBDeleven just never updated or maybe one once every 10 seconds... thats not live data. I ordered a dongle for the torque app.

[old guy]

Get an mini ELM327 bluetooth transmitter for~ $12. Purchase TorquePro from Google Play for $4.95 and you are good to go.

[NitroViper]

Get an mini ELM327 bluetooth transmitter for~ $12. Purchase TorquePro from Google Play for $4.95 and you are good to go.

I went out about 2 hours after and pre start was 92psi. the engine stuttered some. Im wondering if its even the high pressure fp... why would it be, its not even in motion before the start. The pump in the gas tank seems like it would be priming the system to me.

[old guy]

I went out about 2 hours after and pre start was 92psi. the engine stuttered some. Im wondering if its even the high pressure fp... why would it be, its not even in motion before the start. The pump in the gas tank seems like it would be priming the system to me.

I will observe mine in the morning after sitting all night. As you can see in my video it was at a low pressure and immediately upon start up the high pressure pump kicked in and went to a little over 1,000 psi before it got regulated back to 850 psi. That all occurred in the first second of start up.

How long did it take your fuel pressure to reach the 710 psi where yours appears to have leveled out?

[NitroViper]

I will observe mine in the morning after sitting all night. As you can see in my video it was at a low pressure and immediately upon start up the high pressure pump kicked in and went to a little over 1,000 psi before it got regulated back to 850 psi. That all occurred in the first second of start up.

How long did it take your fuel pressure to reach the 710 psi where yours appears to have leveled out?

Last 2 times I went to start the car I opened the door and heard no fuel pump priming. Both times the psi was 92 to 100psi. It stuttered a tiny bit this time at 100psi. Wonder why the fuel pump primes only sometimes.

[old guy]

Last 2 times I went to start the car I opened the door and heard no fuel pump priming. Both times the psi was 92 to 100psi. It stuttered a tiny bit this time at 100psi. Wonder why the fuel pump primes only sometimes.

This morning I did not hear my low pressure fuel pump prime when I opened the door. My fuel pressure measured 110 psi prior to starting the engine. Within one second of hitting the start button the fuel pressure peaked at 1250 psi and immediately dropped to 860 psi where it remained until the fast idle returned to normal idle. At that point the fuel pressure dropped to 570 psi.

So pretty much the same as yesterday.

My speculation is that as long as the residual system pressure is above a certain amount the ECM does not feel the need to prime then system. The high pressure pump runs off of a cam lobe so it can provide pressure pretty much instantaneously as evidenced by the jump from 110 psi to 1250 psi in under one second. So at this point I don't think it really matters if the residual pressure is 100 psi or 570 psi. As long as the LPFP can provide enough fuel for the HPFP to reach the desired set point in the first second of operation it really shouldn't matter.

You noted that your cold start fuel pressure was around 750 psi. Mine is about 150 psi higher than that. I wonder if that may have anything to do with your cold start stuttering? I will continue to look at mine on hot and cold starts and reply back to this thread if I notice any variations from what I have already recorded.

[old guy]

One test, after driving (engine hot) take note of the hpfp pressure at idle, turn engine off, over the course of 5 minutes the pressure should build to 2-3xs idle pressure, if it doesn’t, or it drops, its either an injector (if fuel in oil) or the hpfp is on its way out.




Just got back from the liquor store;-). When I got there I noted the fuel pressure at idle was 570 psi. Turned off the ignition and observed for around one minute. Fuel pressure increased to 700 psi. By the time I got back to the car about 10 minutes later the residual pressure was 1375 psi.

LPFP did not prime when I opened the door.

[NitroViper]

I went out today first time since yesterday and heard the pump prime. The pressure was a 98psi and the car started normal. It stayed around 760psi and dropped to about 570 after a minute. Its hard to know if it peaked higher then 760 because the obdeleven app freezes. I should have torque app and dongle tomorrow. HPFP is here today and im not installing it until I see some proof mine is low.

I need to test it when the car stutters so bad that the check engine light comes on, but that doesnt happen alot.

[dalmation53]

I would change the HPFP. if problems persist send it back..
I went out today first time since yesterday and heard the pump prime. The pressure was a 98psi and the car started normal. It stayed around 760psi and dropped to about 570 after a minute. Its hard to know if it peaked higher then 760 because the obdeleven app freezes. I should have torque app and dongle tomorrow. HPFP is here today and im not installing it until I see some proof mine is low.

I need to test it when the car stutters so bad that the check engine light comes on, but that doesnt happen alot.

[Novarider]

The HPFP should be a maintenance item anyway IMO.

[Traptalk]

I have a brand new oem Bosch lpfp and screen from when I did my walbro 450 swap you could drop into your existing basket. Then pick up a new filter and be good as new

Edit : actually I forget you got to cut some plastic to remove the pump fully so would have to get creative with putting it back together

[NitroViper]

I have a brand new oem Bosch lpfp and screen from when I did my walbro 450 swap you could drop into your existing basket. Then pick up a new filter and be good as new

You giving that away for testing purposes? lol

[Traptalk]

You giving that away for testing purposes? lol

Note the edit lol

[Traptalk]

If you’re up for the challenge tho, just cover shipping since I have zero use for it now

[Traptalk]

The pump easily disassembles to this point

https://i.postimg.cc/sf0GNgtk/6-EAD3770-C7-C5-4-D0-D-9-C87-9550-F8500037.jpg

This bracket is what you’ll have to modify to remove and swap the pumps

https://i.postimg.cc/d15ZvsDT/2-DC1-E2-ED-1715-46-D0-BBB4-D96-D35-A334-B6.jpg

A new pump is like $200

[NitroViper]

I don't know if this helps at all but here it is. This (crappy) video was taken on a cold start 2013 2.0 TFSI. The ambient temperature was 89° f.

What could be noteworthy:

- Prior to ignition the fuel pressure was 362 psi.

- Upon ignition the fuel pressure was 850 psi → 860 psi with fast idle ~1200 rpm

- Timing advance at -17° → -20° ATDC

-Charge voltage ~ 13.5v

-AFR remains around 14.7. O2 equiv. ratio remains at 1.

- At approximately 1 minute the rpm dropped to 750 and the fuel pressure dropped to 560 psi → 570 psi

-Timing advance increased to +3° → +5° BTDC

EDIT: Went back and performed a warm start. (No crappy video)

- Fuel pressure at 650 psi

- Upon ignition fuel pressure dropped to 560 psi → 570 psi and remained there.

-Timing advance +3° → +5° BTDC

- No stuttering with either cold or warm start.

Got my torque app, not sure what you added exactly but do these look right? I like how it stays live. OBDeleven wont stay live without freezing. What a watse of money. Only thing it was good for is enabling AUX permanently.

The car ran like crap for a few seconds, dunno if you can tell. I used an app called V Recorder to record my phone screen.


https://youtu.be/wmM8mKiw9wY

[NitroViper]

The pump easily disassembles to this point

This bracket is what you’ll have to modify to remove and swap the pumps

A new pump is like $200

Ive took apart and put pumps like that before to work on peoples cars, its a pain sometimes. Sometimes it works and sometimes it doesnt because of the heat shrunk tubes.I actually have a fuel filter already. The guy had one in the trunk, Ill bet money he had this problem and never told me.

[Traptalk]

Ive took apart and put pumps like that before to work on peoples cars, its a pain sometimes. Sometimes it works and sometimes it doesnt because of the heat shrunk tubes.I actually have a fuel filter already. The guy had one in the trunk, Ill bet money he had this problem and never told me.

No heat shrink tubes on this, won’t have to splice any wires either

[NitroViper]

No heat shrink tubes on this, won’t have to splice any wires either

I mean if the HPFP doesnt fix it it would be worth a try and maybe help other ppl figure out this issue. Seems like there is many here.

[dalmation53]

Bro if you putting your F23l your car at 100k the pump is tired same like mine. You should indeed change it and let us know since. you already bought the pump. once your issue is resolved we would all appreciate it and change it as well.
I mean if the HPFP doesnt fix it it would be worth a try and maybe help other ppl figure out this issue. Seems like there is many here.

[old guy]

Got my torque app, not sure what you added exactly but do these look right? I like how it stays live. OBDeleven wont stay live without freezing. What a watse of money. Only thing it was good for is enabling AUX permanently.

The car ran like crap for a few seconds, dunno if you can tell. I used an app called V Recorder to record my phone screen.



Was that on a warm start?

I will take a closer at a warm start on mine tomorrow. One thing that stands out to me is that your ignition timing is initially a little ATDC. I believe mine is stayed around 3° → 5 ° BTDC on a warm start but will confirm. I only saw ATDC timing with the fast idle and 860 psi fuel pressure.

Your fuel pressure looks fine as compared to mine on a warm start. Bounces around 560 → 570 psi.

[Traptalk]

Idk if obdeleven allows but you could watch your high pressure fuel request and actual and see if your coming up short or dropping pressure at wot.

These mechanical pumps really don’t outright fail but the metering valve can and the internal seals can breaks and leak into the oil and cause loss of pressure.

If it’s only in cold start after the cars been sitting could be the lpfp loosing pressure and gas leaking back into the tank. Can try cycling the power on a few times with the key to build prime pressure before starting the car and see if that eliminates it.

I had a stutter once, doesn’t sound as bad as yours. Was a single hiccup not 3-4 seconds of stutter. Seemed to be related to a tiny boost leak that was hard to find. Found it out of chance actually.

[NitroViper]

Was that on a warm start?

I will take a closer at a warm start on mine tomorrow. One thing that stands out to me is that your ignition timing is initially a little ATDC. I believe mine is stayed around 3° → 5 ° BTDC on a warm start but will confirm. I only saw ATDC timing with the fast idle and 860 psi fuel pressure.

Your fuel pressure looks fine as compared to mine on a warm start. Bounces around 560 → 570 psi.

That was a semi warm start, about an hour and a half after driving it.

[old guy]

Understood. Since we both now have TorquePro lets set the same info on one page so we can compare a cold and warm start.

I will set mine to the following:

RPM
Block temperature
Timing Advance
Fuel Pressure
Vacuum
AF Ratio

Then we can compare any differences on a hot and cold start. I won't be able to get on it until tomorrow afternoon. Heading out for a 56 mile bike ride on the local Rails to Trails in the morning [:D]

[NitroViper]

Understood. Since we both now have TorquePro lets set the same info on one page so we can compare a cold and warm start.

I will set mine to the following:

RPM
Block temperature
Timing Advance
Fuel Pressure
Vacuum
AF Ratio

Then we can compare any differences on a hot and cold start. I won't be able to get on it until tomorrow afternoon. Heading out for a 56 mile bike ride on the local Rails to Trails in the morning [:D]

Ill set mine like that, its just mine is so random who knows what it'll say lol. Tomorrow ill record it before i drive and then ill come home shut the car off and do a warm restart in a few minutes.

I dont see a block temp. I see a coolant temp tho.

[old guy]

Ill set mine like that, its just mine is so random who knows what it'll say lol. Tomorrow ill record it before i drive and then ill come home shut the car off and do a warm restart in a few minutes.

I dont see a block temp. I see a coolant temp tho.

Sounds good. Coolant temp is same as block temp.

I will probably have to take a nap when I get home before I can record mine (being an old guy;-)

[NitroViper]

Sounds good. Coolant temp is same as block temp.

I will probably have to take a nap when I get home before I can record mine (being an old guy;-)

below is how I have it set up right now.

https://cdn.discordapp.com/attachments/215674115963617280/740377162619682883/Screenshot_20200804-211054.png

[old guy]

Okay. I'll set mine the same.

[old guy]

Here's my cold start. I noticed that the pid for vacuum isn't reading accurately so I picked the vacuum/boost for the warm start. It appears to be accurate. A/C was turned off. Pump did prime when I opened the door. I also added the STFT so you can see when it goes from open loop to closed loop.


https://youtu.be/ufkHjWsBLpw

As noted I used a different pid for the vacuum/boost reading. Pump did not prime when opening the door. I also noted that the timing advance did bounce between ATDC and BTDC.


https://youtu.be/9vcllAiJf74

[NitroViper]

Here's my cold start.

I went out to do that today and the engine started normal. There really is no reason for me to post that reading becuase its not showing whats wrong if you know what I mean. Ill keep trying to get that crappy cold start every few hours. Your cold start psi was 295psi. Ive never seen mine that high.

Ill edit this thread as soon as I can getting a bad stuttering cold start.

[old guy]

I went out to do that today and the engine started normal. There really is no reason for me to post that reading becuase its not showing whats wrong if you know what I mean. Ill keep trying to get that crappy cold start every few hours. Your cold start psi was 295psi. Ive never seen mine that high.

Ill edit this thread as soon as I can getting a bad stuttering cold start.

Understood.

I will continue to note my cold start residual fuel pressure to see how much it varies.

[JLAllroad]

One test, after driving (engine hot) take note of the hpfp pressure at idle, turn engine off, over the course of 5 minutes the pressure should build to 2-3xs idle pressure, if it doesn’t, or it drops, its either an injector (if fuel in oil) or the hpfp is on its way out.


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@NitroViper and @Oldguy, have either of you done this and compared?


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[old guy]

@NitroViper and @Oldguy, have either of you done this and compared?


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Read post #81 ;-)

[NitroViper]

@NitroViper and @Oldguy, have either of you done this and compared?


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Yea mine was like 1600 once, I was suprised to see that after having my car off for a bit.

[old guy]

I went out to do that today and the engine started normal. There really is no reason for me to post that reading becuase its not showing whats wrong if you know what I mean. Ill keep trying to get that crappy cold start every few hours. Your cold start psi was 295psi. Ive never seen mine that high.

Ill edit this thread as soon as I can getting a bad stuttering cold start.

Cold start today was 110 psi.

[NitroViper]

My car wasnt stuttering enough to catch it on a cold start with our torque icon placement So I put the one that did stutter in this video. I been putting off changing the HPFP until this test is done but my car doesnt seem to want to stutter with testing going on lol.

If I slow it down or pause it the major difference I see is the timing between the cold start stutter and the cold start good. In Editing I lined all all engine starts at the same exact moment. The sound in the video is from the stuttering start.


https://youtu.be/UVHvMvVeWlw

[Smac770]

That’s only one of the fuel filters. How do you replace the inlet pick up screen?

You’d have to disassemble the entire to pump and clean the screen and reuse it to really do it proper

Eh, that's a bit of a stretch, but not something to be disregarded. It's like saying there's two air filters, when there's only one. The snow screen is just that, a screen. Which does need to be cleaned from time to time (it's actually in the Audi maintenance schedule).

Is there an inspection and/or cleaning process for the inlet screen? I have no idea. Never seen anyone refer to the screen before.

[old guy]

Your cold start stutter video doesn't show the coolant temperature. It is acting like a warm start. The fuel pressure and timing as well as the RPM's are similar to all of my warm starts. My cold starts all have the very retarded timing, higher fuel pressure and higher RPM's.

Can you capture a stuttering cold start that also shows the coolant temperature? I know that on my A4 B6 a defective coolant temperature sensor will cause starting problems. It could be that you have a cold engine but the CTS is indicating to the ECM that it is actually a warm start and consequently the ECM isn't providing the fuel necessary for a cold start.

[NitroViper]

Your cold start stutter video doesn't show the coolant temperature. It is acting like a warm start. The fuel pressure and timing as well as the RPM's are similar to all of my warm starts. My cold starts all have the very retarded timing, higher fuel pressure and higher RPM's.

Can you capture a stuttering cold start that also shows the coolant temperature? I know that on my A4 B6 a defective coolant temperature sensor will cause starting problems. It could be that you have a cold engine but the CTS is indicating to the ECM that it is actually a warm start and consequently the ECM isn't providing the fuel necessary for a cold start.

Ive been trying every since we decided on an icon setup in torque to get a cold start stutter. It just hasnt happened yet and ive tried many times. Im sure on that cold start stutter the coolant was cold like the regular cold start tho. But I couldnt see it, maybe it didnt.

[old guy]

Ive been trying every since we decided on an icon setup in torque to get a cold start stutter. It just hasnt happened yet and ive tried many times. Im sure on that cold start stutter the coolant was cold like the regular cold start tho. But I couldnt see it, maybe it didnt.

If that stutter start was indeed with cold coolant I suspect your CTS may be reading incorrectly. I will continue to watch mine closely to see at what temperature the start up protocol goes from a cold start settings to a warm start settings and we can compare.

[NitroViper]

If that stutter start was indeed with cold coolant I suspect your CTS may be reading incorrectly. I will continue to watch mine closely to see at what temperature the start up protocol goes from a cold start settings to a warm start settings and we can compare.

Ill keep trying over the next few days. I have a feeling it isnt my HPFP and ill send that back if its something else, but you can see the timing difference. That stuttering start was indeed cold coolant. With the timing being that different youre right the ECU might be thinking the car is already warm and fumbles on start because the coolant temp sensor is stuck. If it was the HPFP the timing would still match.

I cant seem to find one on fcpeuro for some reason.

https://www.fcpeuro.com/products/vw-sender-genuine-vw-06a919501a

I think thats correct even tho the site says it doesnt fit my car... Just ordered one screw it. The timing is a huge difference and make me thing this is the issue.

I went out there a couple hours ago and the coolant temp read 106.6... I just went out a few minutes ago to test it and it said 107... thats about 4 hours of cooling... suspect?

[old guy]

I believe it is item #6. Clicky click (https://7zap.com/en/catalog/cars/Audi/brand/3/0/Audi%20A5/Audi%20A5%20(2008%20-%202016)/Audi/OVdFVVJud1B6WEFGRU9Db2RmTzBNQT09--/6bbffde8b5b8077d2d0a5796da6eea3c:679532b3fb6f272ee 9b4372ef500a023/manufacturer/1/855121010::121002)

107° after 4 hours sounds about right to me.

I just checked mine after sitting overnight. Outside house thermometer reads 72°. Dash display reads 72°. Coolant temperature sensor reads 75°. Residual fuel pressure reads 112 psi.

[Theiceman]

older generations of Audis used a 4 pin sensor and the sensor was essentially split in half, one feed feeding the ECU and the other half feeding the gauge. so essentially to your point one side could fail and the other half would be fine. On our generation of car they have gone to a two pin connector with only one coolant temp feed. It feeds the ECU and that data us routed to the gauge. Also they don't really get " stuck" .
All that to say i think you are on the wrong path.
But if you do decided to change it its not too bad to get too and don't forget the Oring.

[old guy]

Yep. I'm very familiar with the 4-pin sensor. I've replaced it several times on my a4 B6.

What I find interesting is that Nitro's stuttering cold start had all the conditions (fuel pressure, timing advance, RPM's) of a warm start. I'm speculating here but typically you provide more fuel on a cold start. Thus the higher fuel pressure. So the question is, why did the ECM perform a warm start on a cold engine?

CTS reading is one thing that comes to mind. Then again it may have nothing to do with it at all. Fortunately it is pretty easy to change out.

[NitroViper]

170° is pretty hot after 4 hours. seeing the coolant temp normally gets to 192° about. Was fine today on cold start with starting coolant temp of 76.

Last night I went out again and the temp was 92° the fuel pressure was 72psi... that is the lowest ive ever seen it. It stuttered at the start.

[old guy]

170° is pretty hot after 4 hours. seeing the coolant temp normally gets to 192° about. Was fine today on cold start with starting coolant temp of 76.

Last night I went out again and the temp was 92° the fuel pressure was 72psi... that is the lowest ive ever seen it. It stuttered at the start.

I agree that 170° is too high after 4 hours. You inadvertently typed 107°.

Did you observe how quickly the fuel pressure increased at the start? Did it take several seconds to get up to your normal cold start pressure?

[NitroViper]

107° lol.
I dont know, sometimes things look normal when it stutters and sometimes things look abnormal when it starts normally. The only video that looks wacky to me with the one with the timing way off. Ill keep trying but I might just throw the HPFP on and put in a new temp sensor.

[dalmation53]

Hey Nitro check this out. i tried something today actually been doing this a week. before starting the car push the accesories on and off 3 times. let the fuel pump prime 3 times on the 4th start it. it should not misfire on cold start up this makes me think is either HPFP or low pressure fuel pump.

[NitroViper]

Hey Nitro check this out. i tried something today actually been doing this a week. before starting the car push the accesories on and off 3 times. let the fuel pump prime 3 times on the 4th start it. it should not misfire on cold start up this makes me think is either HPFP or low pressure fuel pump.

I am going to change the HPFP and coolant temp sensor this week when I put the k04 on. Im sick of trying to figure it out.

[Benji16]

Lol i mean dalmation has been saying to change the HPFP for quite a while.
I am going to change the HPFP and coolant temp sensor this week when I put the k04 on. Im sick of trying to figure it out.

[NitroViper]

Lol i mean dalmation has been saying to change the HPFP for quite a while.

Ive had the HPFP for a while... I wasnt changing it because we were testing... to maybe find the issue for future and current users with the issue. Im about to do it anyways.

[dalmation53]

please please do. i have been waiting for you to do this lol...
Ive had the HPFP for a while... I wasnt changing it because we were testing... to maybe find the issue for future and current users with the issue. Im about to do it anyways.

[NitroViper]

please please do. i have been waiting for you to do this lol...

I can almost guarantee it wont fix it because of the timing readings... I am only putting it in because I am going to have more power and want reliability. Ill be changing the coolant temp sensor as well so if it does get fixed I wont be able to tell you which it was.

[NitroViper]

please please do. i have been waiting for you to do this lol...

I changed it today, wont know for a few days I guess. Looks a little strange installed but it runs fine. Ill post a pic later. It looks a little crooked but that bracket just wiggles all over the place.

[dalmation53]

yeah take a pic of it i'm not sure what you mean?
I changed it today, wont know for a few days I guess. Looks a little strange installed but it runs fine. Ill post a pic later. It looks a little crooked but that bracket just wiggles all over the place.

[NitroViper]

Seems fine I guess, just didnt expect that gap.

https://cdn.discordapp.com/attachments/518596326900891648/742871252083015700/20200811_175100.jpg

[Traptalk]

Hey Nitro check this out. i tried something today actually been doing this a week. before starting the car push the accesories on and off 3 times. let the fuel pump prime 3 times on the 4th start it. it should not misfire on cold start up this makes me think is either HPFP or low pressure fuel pump.

I think I told ya to try this a couple pages back lol

[NitroViper]

So much for that experiment... $250 wasted.

[JLAllroad]

So much for that experiment... $250 wasted.

I wouldn’t say wasted, I consider these HPFPs a maintenance item at 100k.

Additionally, once you get a tune you quickly find the weak links, and this can be one of them.

Although, would normally want the car at 100% before the tune to limit variables.

Do you have any misfires when driving or wot?



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[NitroViper]

I wouldn’t say wasted, I consider these HPFPs a maintenance item at 100k.

Additionally, once you get a tune you quickly find the weak links, and this can be one of them.

Although, would normally want the car at 100% before the tune to limit variables.

Do you have any misfires when driving or wot?

In the 2 cold starts since installing the HPFP its stuttered so bad the check engine light comes on... Then runs fine after 30 seconds or so when the car revs down.

Car runs perfectly fine after it revs down from its high idle at starting. It is only cold starts and until the car idles down that it messes up. I cant believe in all these years no one has a fix for this when it seems to be common. Ill be changing the coolant temp sensor when I change the turbo.

[Traptalk]

Try building prime pressure. It’s free

[NitroViper]

Try building prime pressure. It’s free

Yea its free but will never tell you whats wrong. It gotta be either the LPFP or Coolant temp sensor...

[Chillaxin]

Maybe I should clean the MAF.

On cold start up the engine is running in open-loop control since the O2 sensors are not warmed up and giving good info. Doubt the MAF would cause stuttering on the first 3-4 seconds of cold start. Not a bad idea to clean it once a year though.

[old guy]

On cold start up the engine is running in open-loop control since the O2 sensors are not warmed up and giving good info. Doubt the MAF would cause stuttering on the first 3-4 seconds of cold start. Not a bad idea to clean it once a year though.

Agreed. If you watch my cold start video you can tell when the ECM goes into closed loop. About 30 seconds after the initial start the STFT begins to make adjustments. That occurs when the ECM goes into closed loop.

For the past week I have been closely observing the residual fuel pressure at every cold start. If the car sits overnight the LPFP will engage and the pressure is typically 110→114 psi when I start cranking the engine over. Within less than one second the fuel pressure will peak over 1,000 psi and then drop to 860 psi along with the fast idle.

Cold starts are always smooth with no issues.

Nitro's cold residual pressures seem to be a little lower than mine. Once his engine starts his fuel pressures also seems to level out in the first second. However, his cold start pressure seems to level out at a lower psi than mine on a cold start.

I have no idea if this is a significant difference or not. My gut feel is that it is something other than fuel pressure that is causing your cold start stutter. Did you replace your fuel injectors when you did your recent rebuild? I wonder if you have an under-performing injector? Cold start fueling is pretty critical and having one of your injectors providing a crappy spray pattern could possible be a contributing factor.

[JLAllroad]

My gut feel is that it is something other than fuel pressure that is causing your cold start stutter. Did you replace your fuel injectors when you did your recent rebuild? I wonder if you have an under-performing injector? Fueling is pretty critical and having one of your injectors providing a crappy spray pattern could possible be a contributing factor.

This, in part, is why I was inquiring on misfires(logged) as I believe coils/plugs/injectors are new(er) doesn’t necessarily mean that they are all “good”.


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[NitroViper]

Did you replace your fuel injectors when you did your recent rebuild? I wonder if you have an under-performing injector? Cold start fueling is pretty critical and having one of your injectors providing a crappy spray pattern could possible be a contributing factor.

Plugs are new and gapped, injectors are new bosch, intake/dividers and valves all perfectly clean no carbon.
This was happening before I ever removed the engine.

[old guy]

Plugs are new and gapped, injectors are new bosch, intake/dividers and valves all perfectly clean no carbon.
This was happening before I ever removed the engine.

Damn.... I'm running out of ideas.

How long does the stuttering last when it occurs? 20 seconds? All 30 seconds of the cold idle?

[NitroViper]

Damn.... I'm running out of ideas.

How long does the stuttering last when it occurs? 20 seconds? All 30 seconds of the cold idle?

The bad stuttering lasts maybe 2-3 seconds, once in a great while itll trigger a check engine light, obvious misfires. Light goes right off tho. After that sometimes the idle will have little hiccup here and there, once the engine revs down its completely normal.... I swear it has something to do with the engine reading the block temperature wrong, thats what the timing told me in that one video.

If its not cold its perfect, to me it seems like if it was the HPFP it would do it no matter what the temp is, it doesnt change RPMS or pump speed on different start temps. The engine changes the speed but the pump doesnt function any different.

[old guy]

Well lets see what happens when you change the CTS.

[JLAllroad]

How old is your battery? Has it and the charging system been tested?

Guessing the voltage would be lowest and demand would be highest when cold.


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[NitroViper]

How old is your battery? Has it and the charging system been tested?

When I bought the car I wondered about the battery because when you start it and the dome lights are on they sort of flash. I had advance auto test it and they said its fine. I dont trust the battery since ive owned it to tell ya the truth. Im not about to throw another $200 at it guessing at the moment tho. We will see how it goes after a few days and the new turbo and CTS is in. I know the turbo and stuff has nothing to do with it but ill be changing the cts when the antifreeze is drained.

[Traptalk]

Yea its free but will never tell you whats wrong. It gotta be either the LPFP or Coolant temp sensor...

If building prime pressure stops the issue than your pump is obviously at fault...

Which would also explain why the warm starts are ok. When the car sits for a long time you lose pressure and fuel leaks back into the tank.

I’m telling you man just try it and see.

[NitroViper]

If building prime pressure stops the issue than your pump is obviously at fault...

LPFP? My car has been at the correct pressure many times cold and still stuttered. I guess we cant go off app readings then if priming it fixes it. I was the guineapig and bought and installed the HPFP like everyone wanted. Where is the guineapig for the LPFP?

[dalmation53]

Me i am the guinea pig. I replaced my LPFP when i first got my A5 becuase it was starting to show signs of failure with loss of power. that fixed it 100% but not my cold start misfires. still on original HPFP.
LPFP? My car has been at the correct pressure many times cold and still stuttered. I guess we cant go off app readings then if priming it fixes it. I was the guineapig and bought and installed the HPFP like everyone wanted. Where is the guineapig for the LPFP?

[Novarider]

Have you changed the pcv? You can use a vacuum gauge to test if it's functioning properly.

[Traptalk]

LPFP? My car has been at the correct pressure many times cold and still stuttered. I guess we cant go off app readings then if priming it fixes it. I was the guineapig and bought and installed the HPFP like everyone wanted. Where is the guineapig for the LPFP?

I already offered you a free one lol

[NitroViper]

I already offered you a free one lol

Yea but we never talked about sending it, how much you think shipping would be? a pre paid box from usps? If the coolant temp sensor doesnt fix it thats the only other thing I could think of. Youre in Buffalo, just drive 2 hours and install it for me because im lazy lol.

[Traptalk]

Yea but we never talked about sending it, how much you think shipping would be? a pre paid box from usps? If the coolant temp sensor doesnt fix it thats the only other thing I could think of. Youre in Buffalo, just drive 2 hours and install it for me because im lazy lol.

I bet I could fit in the $7 or $8 flat rate box. Would have to stop in and check. Post is super slow right now. Have a priority mail usps package going on a week late right now.

Yeah I’m in buffalo lol pump is free but i didn’t mention labor was

Maybe if can get some free time one weekend soon, have some extra clips for the back seat as well and a tool to remove the union nut

[NitroViper]

I bet I could fit in the $7 or $8 flat rate box. Would have to stop in and check. Post is super slow right now. Have a priority mail usps package going on a week late right now.

Yeah I’m in buffalo lol pump is free but i didn’t mention labor was

Maybe if can get some free time one weekend soon, have some extra clips for the back seat as well and a tool to remove the union nut

I can do it just being lazy. Of course you need a special tool, audi... wtf lol.

[Smac770]

Just rent it from AutoZone.
https://www.autozone.com/loan-a-tools/loaner-fuel-pump-replacement-kit/oemtools-fuel-pump-replacement-kit-6-pack/605758_0_0
Unless you plan to buy the real Audi one with four prongs, which will no doubt be worlds better. But the job is still easily done with the AZ tool.

I've never replaced the bench clips; maybe it's a "might break" part. You can certainly pick them up after the fact if it turns out you need them.

[NitroViper]

Well, the k04 is in and while doing that I replaced the coolant sensor. Even after the k04 tune and a new coolant temp sensor it still starts like crap on cold start. I didnt expect the tune to fix it but was hoping there was a chance lol. I logged it below, listen to how far the engine bogs down.... My car's exhaust also sounds different in videos now becuase of the high flow cat.


https://youtu.be/Quw_sABj0yY

[old guy]

The only significant difference that I see between your rough cold start and my smooth cold start is that your fuel pressure is about 150 psi less than mine. You reach your operating pressure immediately but it seems to level out in the low 700 psi range whereas mine stays around 860 psi.

Once dropping to low idle both of our pressures stabilize around 570 psi at idle.

I have no idea how you would increase your cold start fuel pressure. I'll poke around a little and see if I can find any info on the subject. Who knows, maybe Smac770 will be bored and need a new challenge [:D]

[Chillaxin]

Just rent it from AutoZone.
https://www.autozone.com/loan-a-tools/loaner-fuel-pump-replacement-kit/oemtools-fuel-pump-replacement-kit-6-pack/605758_0_0
Unless you plan to buy the real Audi one with four prongs, which will no doubt be worlds better. But the job is still easily done with the AZ tool.

I've never replaced the bench clips; maybe it's a "might break" part. You can certainly pick them up after the fact if it turns out you need them.

Both of mine definitely broke when removing my rear seat...FYI

[Smac770]

I only see a burst to 50 bar (5 MPa, 5000 kPa, 725 psi) during engine start, and just 40 bar (4 MPa, 4000 kPa, 580 psi) during high idle as well as normal idle.

As for sitting cold fuel pressure, mine will be 4.25 bar (425 kPa, 61.6 psi) before a cool start and as low as 3.25 bar (325 kPa, 47 psi) before a cold start.

What I notice in Nitro's latest video is that ignition timing is really advanced during the stalling out. I don't know if the timing is a reaction to the stalling, or a cause. But on mine, I see only a minor blip to the positive advance just as the fuel pressure hits 50 bar and starts to turn south towards 40 bar. This lasts for only a quarter second. All the rest of the time, my ignition timing is mild negative. As it slows the idle down under 1k, the timing goes and stays mild positive.

I see the timing mild positive but it blips high positive (13.x) each moment the idle drops below 750 (climate system on, A/C off) as it appears to be maintaining rpm in the 750-770 range.

Even once I'm driving, I never see double digit negative timing adjustment except rare blips just above idle (8xx rpm). I do get positive values up to 30.

No idea what A THR is (total harmonic resonance?). Also, how is it attempting to compute vacuum? Did you install a pressure gauge on the manifold?


So I don't think fuel pressure is an issue. It looks fine to me. I might log more with different starts. But it takes an overnight wait to get a cold start with long high idle. Also note, I have a B8.0 CAEB. They might have changed runtime parameters in B8.5 CAEx, or also on the CPMx motors.


fuel temperature - any thoughts on where the ECM is making up this value from? Other VAG vehicles have a G81 fuel temp sensor, but like they removed the G410 low pressure line pressure sensor, we also have no G81. I see nothing in the connectivity of the fuel pump to imply a fuel temp signal is overlaid on the fuel level signal from the pump to the J285 (instrument cluster). I notice that the fuel pressure value is available at all times, but the fuel temp value is only active while the engine is running. Engine not running, value is an immediate -48°C. I assume it's the same kind of phantom bologna as the exhaust temp and exhaust temp before cat, since the engine has zero means to measure those. Unless the 02 sensors somehow rely that value.


As for residual pressure on the high pressure rail after shutdown, 2-3 times idle is not even close. It's over four times. I was at 172 bar (~2500 psi) when I stopped logging at around 25 minutes.

[JLAllroad]

When I bought the car I wondered about the battery because when you start it and the dome lights are on they sort of flash. I had advance auto test it and they said its fine. I dont trust the battery since ive owned it to tell ya the truth. Im not about to throw another $200 at it guessing at the moment tho. We will see how it goes after a few days and the new turbo and CTS is in. I know the turbo and stuff has nothing to do with it but ill be changing the cts when the antifreeze is drained.

You should be able to log voltage both pre start and running, compare to @OldGuy. If found to be low you could always do a cold start with a jump pack if you have one.


Sent from my iPhone using Audizine (http://r.tapatalk.com/byo?rid=87676)

[old guy]

You should be able to log voltage both pre start and running, compare to @OldGuy. If found to be low you could always do a cold start with a jump pack if you have one.



I will note mine at my next cold start. My battery is a about 1 year old.

[old guy]

Car has been sitting since noon yesterday.

Battery voltage 12.2 Immediately after start went to 13.9 charging rate.

LPFP primed to 117 psi. Upon starting pressure peaked at 1,275 psi and immediately dropped to 860 psi within the first second.

High idle at 1300 rpm. When idle dropped to 750 rpm the fuel pressure dropped to 570 psi.

[NitroViper]

3 cold starts so far after putting the Coolant temp sensor, k04, and tune. Every one of them bad stuttering for a few seconds. Check engine light went on for a second once. But that's just a misfire code that goes away. Lets hope this isnt a trend because before all that was changed it was just random.

[Smac770]

Some data from capturing fuel pressure and ignition timing from a variety of starts.
red - many hours cold start that had quite a bit of kicking in the first few seconds and then again from time to time throughout the high idle; as always, gets smooth once it goes normal idle
orange - many hours cold start that was plenty smooth
green - about 7 hours since last start, we see it went high idle fuel pressure but warm start ignition timing
purple - about 5 hours since last start, doesn't go high idle
blue - about 15 minute since start, so the fuel pressure starts out around 160 bar rather than the 4.3bar (430kPA) that the others start from

I was experimenting with turbo and group uds and such trying to get a decent fine resolution to the data, but either VCDS cannot do it or the ECM, when sending data through the J533 to the OBD port, cannot do it. You can get lots of samples per second, 30 in one instance, but you just end up with a lot of repeated data values. Thus why there's a lot of horizontal flats to the data instead of sharp points.

First 2.5sec:
193267

Movement of the FP (fuel pressure) lines from "0" would indicate cranking, movement of the IT (ignition timing) lines from 0 would indicate ignition. I suspect the light purple FP line is late because of the data sample resolution issue noted above. We see red took a longer crank than the others, which I remember being the case. Sounded like 4 cycles rather than the normal 1-2. Still plenty quick to be "in spec", I feel.

We see the two very cold starts burst past 60 bar and then come back down to the high idle 50 bar value. The two cool starts come up towards 50 bar, but then split on their path. Purple 5hr drops down to the standard idle 40 bar (as did the rpms to normal 750rpm, for me), while green 7hr takes its time working back towards 50 bar as it went high idle (1200rpm). Blue doesn't show up yet, it's still falling from that heat soaked 160 bar.

The timing for all goes negative on ignition, does some bouncing around, then we see the two very cold starts head off to the high negative space while the rest are in the mild negative space, eventually moving into the mild positive space.


19-37 sec:
193268

This is really just to show the steady state. We see the green 7hr timing, where it's running high idle, is in the 6-11 positive range. The purple 5hr timing, which is running normal idle, is the same pattern, but in the normal idle range of 0-5 positive. Red and orange are doing their thing in the negative 16-18 space. Notice the wave on that light purple fuel pressure line. Mine has always idled, in the high or normal spec, at around .2 to .05 bar below specified.

First 14 sec:
193269

Expansion of the startup to show that transition to the steady states for ignition timing seen in the previous image.

End of high idle:
193270

Here's the end of the high idle, roughly 62 seconds after ignition. High idle doesn't always last this long, but it did in these samples. At the same time that the rpm moves from 1200 down to 750, we see the fuel pressure actually go up from 50 bar to 60 bar. Old guy mentioned that his high idle runs 60 bar the whole way. I assume this is the transition from the catalyst warmup dual injection mode to the engine warmup dual injection mode. It runs along for about 12 seconds that way, before dropping to normal single injection idle mode at the normal 40 bar fuel pressure.

During that engine warmup phase, we see the timing on the very cold starts come up into line with normal. We see the 7hr green, which was looking like normal idle, but at about +6 degrees compared, is now bouncing around a lot before settling down like all the others around 76 sec in.


So the logged cold start smooth and cold start kicking look, in regards to these parameters, the same. The red did fire up the fuel pressure faster, and did take longer cranking to actually fire up, but these caliber of scan tools are not going to provide the necessary resolution to identify any issues. The engine sees 50 bar for high idle average FP, and it seems fine with that. I imagine the higher pressure value for old guy is a tuning change they made with B8.5. Nothing we can do about that without hacking the ECU tune.

The ECU does not acknowledge any misfires during the cold start, so what is the kicking? No idea. There's no way to confirm if it's a crank spin rate issue without a high resolution scope to monitor the crank position sensor signal. All in all, I don't bother with it; it's not impacting the vehicle operation.

[Smac770]

The forum engine needs to stop messing with attachments smaller than 1920x1080. The images seem to be clear enough for the purpose, but they are not as clean as what I uploaded.

[old guy]

Wow! Excellent work as always[up][up]

I have been observing my cold, intermediate and warm starts for the past week or so. I'm seeing pretty much the same thing that you are recording with the exception of the high idle fuel pressure. On a truly cold start mine stays at ~ 60 bar until the idle drops to normal. Then it stabilizes at ~ 40 bar.

On an intermediate start I believe the residual block temperature determines the advent and duration of the high idle. Sometimes I get a short duration fast idle and other times I get a typical warm start. I need to start recording the temperature to confirm.

I suspect that you are on track with the 60 bar cold start fuel pressure being a B8.5 revision to address some of the stumbling that so many of the B8's seem to experience.

[old guy]

This is interesting. This particular TSB has been showing up on multiple forums when searching for A4 B8 cold start issues.

https://www.audiforum.ca/attachments/a4-b8-typ-8k-2008%96present-78/6397d1324345108-2011-a4-s-line-cold-start-issues-stall.jpg

[Traptalk]

I only see a burst to 50 bar (5 MPa, 5000 kPa, 725 psi) during engine start, and just 40 bar (4 MPa, 4000 kPa, 580 psi) during high idle as well as normal idle.

As for sitting cold fuel pressure, mine will be 4.25 bar (425 kPa, 61.6 psi) before a cool start and as low as 3.25 bar (325 kPa, 47 psi) before a cold start.

What I notice in Nitro's latest video is that ignition timing is really advanced during the stalling out. I don't know if the timing is a reaction to the stalling, or a cause. But on mine, I see only a minor blip to the positive advance just as the fuel pressure hits 50 bar and starts to turn south towards 40 bar. This lasts for only a quarter second. All the rest of the time, my ignition timing is mild negative. As it slows the idle down under 1k, the timing goes and stays mild positive.

I see the timing mild positive but it blips high positive (13.x) each moment the idle drops below 750 (climate system on, A/C off) as it appears to be maintaining rpm in the 750-770 range.

Even once I'm driving, I never see double digit negative timing adjustment except rare blips just above idle (8xx rpm). I do get positive values up to 30.

No idea what A THR is (total harmonic resonance?). Also, how is it attempting to compute vacuum? Did you install a pressure gauge on the manifold?


So I don't think fuel pressure is an issue. It looks fine to me. I might log more with different starts. But it takes an overnight wait to get a cold start with long high idle. Also note, I have a B8.0 CAEB. They might have changed runtime parameters in B8.5 CAEx, or also on the CPMx motors.


fuel temperature - any thoughts on where the ECM is making up this value from? Other VAG vehicles have a G81 fuel temp sensor, but like they removed the G410 low pressure line pressure sensor, we also have no G81. I see nothing in the connectivity of the fuel pump to imply a fuel temp signal is overlaid on the fuel level signal from the pump to the J285 (instrument cluster). I notice that the fuel pressure value is available at all times, but the fuel temp value is only active while the engine is running. Engine not running, value is an immediate -48°C. I assume it's the same kind of phantom bologna as the exhaust temp and exhaust temp before cat, since the engine has zero means to measure those. Unless the 02 sensors somehow rely that value.


As for residual pressure on the high pressure rail after shutdown, 2-3 times idle is not even close. It's over four times. I was at 172 bar (~2500 psi) when I stopped logging at around 25 minutes.



Not sure how fuel temp is measured in vcds but it seems to conflict with the temperature reading from my Bluetooth ethanol content sensor

[NitroViper]

This is interesting. This particular TSB has been showing up on multiple forums when searching for A4 B8 cold start issues.


Hmm my pcv and crank seal are both new.

[old guy]

Hmm my pcv and crank seal are both new.

But not the ECM Flash update?

[NitroViper]

Nope no ecu flash. Ive read somewhere that you dont need it. I dont feel like spending another $150 to test something and it keep doing it. Already wasted $250 on a HPFP for nothing. :(

[Smac770]

Nitro, you have a white cap or black cap PCV on? You just did work on the engine, but prior, did it have a white cap or black cap? I wonder if you have a mismatch to your current ECM tuning. Actually, you have a tune. I wonder how that tune accommodates the adjustment from black cap to white cap.


"We’re following TSB# 2024812/3 for your repairs. The condition is described as an EPC light and idle below 500rpm sporadically at first start of day while stationary, which is exactly your concern. The issue is caused by Engine control module software and the range of crankcase vacuum allowed. The repair includes replacing the crankcase breather valve with an updated part that allows for more vacuum, replacing the front crankshaft seal with an updated part capable of handling the increased pressure, and a SVM (software) update to control the vacuum and resulting readings."

It's probably been in some thread somewhere at some point, but tracking all that down, .... What crankcase vacuum do you read? I wonder if it bounces around on your stalling starts. I would have thought though that they would reduce the vacuum to reduce oil consumption; less pull by the manifold on the oily vapors.

I already have the white cap due to the oil consumption stage 1, so I see the same numbers as old guy for block vacuum at idle. Never watched it at startup.

But do you get an EPC light when it near stalls?

[Smac770]

Not sure how fuel temp is measured in vcds but it seems to conflict with the temperature reading from my Bluetooth ethanol content sensor

Yeah, that's kind of what I'm worried about. No clue how Bosch is generating that value, VCDS is simply reporting the value at that PID. I wish Audi would stop cutting out all the reality sensors.

[NitroViper]

Nitro, you have a white cap or black cap PCV on? You just did work on the engine, but prior, did it have a white cap or black cap? I wonder if you have a mismatch to your current ECM tuning. Actually, you have a tune. I wonder how that tune accommodates the adjustment from black cap to white cap.



It's probably been in some thread somewhere at some point, but tracking all that down, .... What crankcase vacuum do you read? I wonder if it bounces around on your stalling starts. I would have thought though that they would reduce the vacuum to reduce oil consumption; less pull by the manifold on the oily vapors.

I already have the white cap due to the oil consumption stage 1, so I see the same numbers as old guy for block vacuum at idle. Never watched it at startup.

But do you get an EPC light when it near stalls?

I have the white top PCV, I do not have the ECU flash for it. I bought it before I did my engine to see if it helped. I cant remember if it started like crap before I changed it tho.

[Traptalk]

Yeah I thought those white tops were only for the b8.5 or cpma/mb motors 2013+

[NitroViper]

Yeah I thought those white tops were only for the b8.5 or cpma/mb motors 2013+

https://www.rockauto.com/en/parts/%C3%BCro+parts,06H103495AK,oil+separator,11868

it says its for this car.

Maybe ill just replace it with the black top one

[Traptalk]

I don’t see any fitment info in that link

[Traptalk]

https://i.postimg.cc/hG5sQRXd/F8-D74-EFF-9002-4-D69-AFB7-F01-A2-E3-CF6-A2.png

So black top for up to 2012 models and the white top is from that date forward

[NitroViper]

I don’t see any fitment info in that link

you click the part# 06H103495AK and a thing pops up.
FCPeuro has the white top for my 2011.

Easiest cheapest thing for me is to just buy a black top one for my car to see if it fixes the stutter.

[BradyBoi55]

It could be a misfire. If its bad enough it would throw a code for the cel. If its very minor then it is most likely normal. No engine runs perfect. When an engine is cold you see those imperfections because it runs pristine at operating temp. My car has been doing it since I bought it. If its not too bad just keep an eye on it and make sure it doesn't get worse. I was worried about it when I noticed it also.

[NitroViper]

https://www.ecstuning.com/b-hamburg-tech-parts/pressure-control-valve-pcv-oe-06h103495ac/06h103495e~ham/?gclid=Cj0KCQjwhIP6BRCMARIsALu9Lfm_2cYIBnDL0tRtvAL 7wPy_4Ll-lbTihyD6iAMPjzX_0nVkxW5AJpYaArqCEALw_wcB

that page says that doesnt fit my car... but thats the one that came off it. Red gasket with white plunger.

[Smac770]

It's been covered before. Audi changed over the PCV from a black cap on the B8.0 to a white cap on the B8.5 (when exactly did they start using white cap on new builds; ECS implies Mar 31 '12). The difference being the tuning for the block pressure.
But oil consumption stage 1 procedure was to replace the PCV with a white cap, and if the vehicle was a black cap, to flash it so the ECU understands the change and also replace the front crank seal (but not the rear crank seal? Bean counters at work).

B8.0 A5 CAEB cylinder head, we see both the A -> E -> AC -> AH black cap line and the J -> AE -> AK white cap line. And the same parts bulletin 1-84 reference that has never been seen here.
https://audi.7zap.com/en/usa/audi+a5+s5+coupe+sportback/a5co/2011-620/1/103-103049/

If your engine is the original ECU software, it never had the stage 1 for oil consumption performed, the PCV should be the black cap line.

But now we see those work orders for replacing the black cap with the white cap if there was stalling. Could the white cap without matching flash invoke stalling? I'm not even sure how the PCV would cause stalling unless the diaphragm was tearing. In which case, why not just replace the diaphragm (not that a dealership would do that). Was it necessary to go white cap, or were they just trying to replace the black cap at every opportunity?

Well, we've been waiting for someone with (or should be with) black cap to see if swapping to white cap without the flash causes any changes (issues). If you do throw a black cap back on there, I'd be curious what value you see for block vacuum during idle.

[NitroViper]

Im about to order one of these cheap ass black tops from ebay for $20 just to see if the cold start stutter goes away.... When my cars PCV hose popped off the other day during boost the car rant like crap, it didnt want to start at all and just stalled. That tells my the PCV has a huge factor on the way the car runs and maybe starts...

It's just FCPeuro has 2 different ones with the black top for my engine. The one I replaced had a red gasket with a white plunger, they also have a version with a green gasket and a red plunger. Who knows if mine was already replaced before I bought it.
Like I said, the one I took off had a red gasket and white plunger.

RED GASKET
https://www.fcpeuro.com/products/audi-vw-pcv-oil-trp-06h103495e

GREEN GASKET
https://www.fcpeuro.com/products/audi-oil-separator-vaico-06h103495ak

THIS LOOKS EXACTLY LIKE WHAT CAME OFF MY CAR ORIGINALLY. BUT THAT PAGE SAYS IT DOESNT FIT MY CAR.... 2011 A5 2.0T Quattro
https://www.ecstuning.com/b-hamburg-tech-parts/pressure-control-valve-pcv-oe-06h103495ac/06h103495e~ham/?gclid=Cj0KCQjwhIP6BRCMARIsALu9Lfm_2cYIBnDL0tRtvAL 7wPy_4Ll-lbTihyD6iAMPjzX_0nVkxW5AJpYaArqCEALw_wcB

[Smac770]

ECSTuning:
Not sure what ECS is trying to say with "From production date 1/17/2012" for the A5 vs "Fits up to production date 3/31/2012" for the A4. I suspect someone put something in wrong somewhere.

FCPEuro:
E = AC = AH = black cap, and the pics of the red gasket one show a black cap.
J = AE = AK = white cap, and the pics of the green gasket one show a white cap.
I don't understand the confusion.

[Smac770]

https://www.ecstuning.com/Audi-B8_A5-Quattro-2.0T/Engine/Emissions/PCV/

So they are using a transition date of Jan 16 '12 for the A5. Not surprising, the A5 in ROW came out before the A4 and transitioned to B8.5 before the A4. But I'm pretty sure they have the black cap/white cap backwards regarding which is before and which is after the transition date. Call them up and see if they agree.

[NitroViper]

Im talking about the one I took off originally before I put the white cap on. It had a red gasket and white plunger or whatever you want to call that white circle on the under side of the pcv.

You can see the new white top on the left and my original on the right. The right image you can see the red gasket with white plunger. FCPeuro has 2 different versions as I posted above. The ECS site says it doesnt fit but its the same part number and has the white plunger and alot cheaper than FCPeuro site. So I kinda wanna stick the same exact style that came off the car back on the car.
Im about to buy a no name one on ebay for under $20 lol.

193405193406

[JLAllroad]

A few notes

This whole PCV debacle could have been avoided if you would have just answered my question in your original PCV thread.

I wanted to know what part number you had and what you were replacing it with. I asked to determine if either were incorrect for your model/build date understanding the number of revisions over two different paths (black top vs white).

That said without and ECM flash and crank seal (for this purpose) you should have followed the black top path.

“If your vehicle's current breather has part numbers 06H1034695A, 06H103495E, or 06H103495AH "Black Top" then this will be a direct replacement. If you would like to update your crankcase breather to the "Clear Top" you will need to update the front crank seal and update the ECM software level at your local Dealer.”

I know that you are also quoting multiple gasket and valve colors but this is also produced across multiple vendors.

Personally I would stick with OEM given the repercussions of a failure and revision history.

That said, if you purchased via FCP you may want to reach out to see if they will credit you towards an OEM PCV.


Sent from my iPhone using Audizine (http://r.tapatalk.com/byo?rid=87676)

[NitroViper]

ECSTuning:
Not sure what ECS is trying to say with "From production date 1/17/2012" for the A5 vs "Fits up to production date 3/31/2012" for the A4. I suspect someone put something in wrong somewhere.

FCPEuro:
E = AC = AH = black cap, and the pics of the red gasket one show a black cap.
J = AE = AK = white cap, and the pics of the green gasket one show a white cap.
I don't understand the confusion.

I dont know why I didnt notice the AK has a white top lol. Confused myself.


That said, if you purchased via FCP you may want to reach out to see if they will credit you towards an OEM PCV.


I bought it from RockAuto, so im screwed there. They dont have anything in stock anyways.

[NitroViper]

https://www.ebay.com/itm/162028750882

thats insanely cheap to just test it out.

[old guy]

Don't waste your time and $$ reverting to a black top. Go back and reread post #166. The TSB indicated that replacing the PCV breather valve with a white top and an ecu update cured the problem. Going back to the black top simply recreates the exact conditions that were addressed by the TSB in the first place.

Here's some additional info on the TSB. It clearly indicates that when you update the PCV breather you need to update the ECM.

https://i.postimg.cc/rmnsY0gM/svm.jpg

[NitroViper]

Don't waste your time and $$ reverting to a black top. Go back and reread post #166. The TSB indicated that replacing the PCV breather valve with a white top and an ecu update cured the problem. Going back to the black top simply recreates the exact conditions that were addressed by the TSB in the first place.

Here's some additional info on the TSB. It clearly indicates that when you update the PCV breather you need to update the ECM.

Ive read #166, its just I doubt they kept the vehicle for a week to see if it happens. Its very random and sometimes itll goes days without it happening. When these cars were new or even years old I doubt they all started having a cold start stutter problem. They add the PCV to try and remedy the oil consumption issue. Maybe they got lucky it if fixed the cold start stutter for some? So reverting back doesnt really scare me because im sure it would last a few years without issues if it fixes it? I doubt all of the sudden id have another oil consumption issue and thats seems like its the only other issue of that PCV? It would be nice to know tho if it fixed it reverting back. Wouldnt know for weeks tho to be sure. Not saying youre wrong or anything, thats just what Im thinking and $20 isnt much of a gamble.

[old guy]

I would rather deal with an occasional cold start stutter than to put on a cheap PCV combination valve. It just isn't worth the risk. A faulty PCV can cause considerable damage depending upon how it fails.

[NitroViper]

I would rather deal with an occasional cold start stutter than to put on a cheap PCV combination valve. It just isn't worth the risk. A faulty PCV can cause considerable damage depending upon how it fails.

I agree but as much as I keep hearing flash the ECU for $150 and change the front crank seal its worth a try to go backwards. I cant afford the $60 for the ecstuning one at the moment. It just sucks I threw almost $250 away on a HPFP as a test. Im to poor to just keep throwing money at it. I dont care if people judge me about that like they have in the past on here. If it fixed the problem atleast we would know what it was.

[dalmation53]

like a rear main seal [emoji30]
I would rather deal with an occasional cold start stutter than to put on a cheap PCV combination valve. It just isn't worth the risk. A faulty PCV can cause considerable damage depending upon how it fails.

[Smac770]

The black cap PCV is designed for a 20 mbar (.6 inHg) crankcase vacuum. The white cap PCV is designed for a 100 mbar (3 inHg) crankcase vacuum. The white cap appears to be yet another design change for the Gen3 which was backported to the Gen2 for/during MY12. It appears at least two TSB actions discuss converting black cap engines to the white cap:

2027731 - Engine oil consumption too high, originated Nov 2, 2011.
2024812 - EPC light illuminated, low idle on first start of day, originated Aug 10, 2011.

Both involve replacing the black cap with the white cap, replacing the front mail seal, and updating the ECM software. Regarding the ECM, my assumption is the increased vacuum will cause increased air flow through the breather valve, resulting in additional air flow into the intake manifold bypassing the regulation of the throttle body. So the ECM needs to know this modified rate so it can manage the throttle body appropriately to deliver the intended total air volume to the valves. I'm guessing at this. I can't see what other impact the increased vacuum would have that the ECM would need to care about. I also have no idea if the breather hole behind the little valve on the bottom is adjusted on the white cap PCV so that the total breather valve air flow is actually intended to be the same under both vacuum levels. But if that were the case, why does the ECM need to know?

For the purpose of 2024812, which I could not find on NHTSA but one incomplete reference seemed to imply it was only for MY11 vehicles, I assume the reason for the change is to make the variations causing the issue to be smaller relative to the overall design. A small issue is a greater percentage of 20 mbar than it would be of something 5x larger, 100 mbar. I for one, had a black cap to 84k miles and never noticed any rough idle, or any high idle "kicking" like I get from time to time these days.

For the purpose of 2027731, I actually can't see how this helps reduce oil consumption. Maybe this is why I never see anyone saying stage 1 solved their oil consumption. The oil consumption issue from rings is oil getting burned up in the cylinder. Is increasing the vacuum supposed to help suck the gasses in to push the oil back in? If the oil consumption issue was excess oily air getting pulled into the intake track, maybe the greater vacuum and likely faster air flow improved the operation of the coarse and fine oil separators?

But if you replace the black cap with the white cap without the software update, I imagine now you have extra air flowing into the intake manifold and leaning out the situation. As closed loop cannot offset that at startup, you end up with lean mix and possible stalling? Same for having the update and trying to go back to the black cap; now you end up rich at idle. NitroViper, are you noticing any lean at idle fuel trim?

2027731 has a chart for black cap vs white cap software:
193490

I myself have a 2009 with white cap and VCDS reports ...AL 0001. Note, these replace the ECM updates for the 2027082 for the errant P0234 overboost DTCs.


As an aside, it appears there was a problem with white cap PCVs up through MY14, and a campaign 17F9 occurred in Nov '15. It mentions a diaphragm repair kit 06H198542A:
https://www.genuineaudiparts.com/oem-parts/audi-repair-kit-06h198542a
Curious. It is not relevant to black cap, but I suspect so long as you only use the diaphragm (same recommendation if you were using the Dorman kit), it would be fine.

[Smac770]

I also wonder if you have an abnormal leakage air value (IDE01911). I dug up an old log where I was started up around 3.5 and ran up to as much as 4.9 (kg/hr). This would have been white cap days.

There are also IDE01917 and IDE01918, leakage after and before throttle valve. But these just start 0 and eventually change to -1. No idea what to make of those PIDs then.

[NitroViper]

Smac you make my brain hurt lol. Give me a simple answer, try the black top or not? haha

[Smac770]

What is the software info reported for the ECM?

[NitroViper]

What is the software info reported for the ECM?

I dont have VCDS, I have OBDeleven but that app is such a mess I could probably never find it. Im sure it's never been updated Ill go look tho. Hope my IE tune doesnt change it.

[Smac770]

Another thought; if the source of the idle fluctuation is due to excess air ingestion due to the higher crankcase vacuum of the white cap, remove that as a factor. Unplug the pipe from the PCV to the intake manifold and block off that intake manifold opening. See if your starts are any different. If not, it's unlikely the PCV is involved in the issue, I would suspect. Again, guessing, but it's something to try to add data to the whiteboard.

- - - Updated - - -

https://store.034motorsport.com/checking-ecu-tcu-box-code-software-version-audi-volkswagen/

[NitroViper]

193526193525193524

[Smac770]

So if we look back at the chart, AD is the 2011 black cap software. So you should only run the black cap.

I think it would still be interesting to see if the issue changes with the PCV path to the manifold blocked off.

But then it comes down to money for a black cap vs money for a software flash. I go back to your opening statement, "My car has done this even before the rebuild so I am not sure whats up with it." Was that with a black cap? If so, I say go for the software update. You have to spend some coin either way (you don't happen to have your old black cap still around?), you might as well spend the coin on (prospective) progress.

[NitroViper]

So if we look back at the chart, AD is the 2011 black cap software. So you should only run the black cap.

I think it would still be interesting to see if the issue changes with the PCV path to the manifold blocked off.

But then it comes down to money for a black cap vs money for a software flash. I go back to your opening statement, "My car has done this even before the rebuild so I am not sure whats up with it." Was that with a black cap? If so, I say go for the software update. You have to spend some coin either way (you don't happen to have your old black cap still around?), you might as well spend the coin on (prospective) progress.

The black top PCV from ECS is only 59.99 compared to $150 for a flash, they said it could take more than an hour which is complete BS, so it would be more than $150 which is theft for something that takes 15 minutes max and also have to worry about the front crank seal. Even tho crank seal is new I dont know if its the correct one as it came with the timing cover.
I could spend money to upgrade the computer and have the new white top pvc but If I bought a black top PCV i doubt it would ever fail for as long as I own the car personally. I doubt I drive 10k miles a year.

Taking that hose off and plugging the intake everyday on cold starts would suck as a test every day for say a week lol.

I cant remember if the car did it before I updated the PCV that was 3 months ago and I didnt own the car very long before that.

[dalmation53]

My car did the cold start misfires with black top pcv and with white top pcv. Now i don't get no more cold start misfires because the car is broken[emoji23]

[NitroViper]

My car did the cold start misfires with black top pcv and with white top pcv. Now i don't get no more cold start misfires because the car is broken[emoji23]

Did you have the computer flashed? Thats why I dont want to waste money on a PCV because It probably wont fix it. Im sick of just wasting money.

[dalmation53]

Nah bro I didn't even change my crank seal or flashed it and the revision with the white top is genuine. and still did it sometimes. so idk man.
Did you have the computer flashed? Thats why I dont want to waste money on a PCV because It probably wont fix it. Im sick of just wasting money.

[NitroViper]

Nah bro I didn't even change my crank seal or flashed it and the revision with the white top is genuine. and still did it sometimes. so idk man.

Ok since I bought the HPFP it's your turn to buy the original PCV for your car and see if it fixes it once it running lol.

[JLAllroad]

Ok since I bought the HPFP it's your turn to buy the original PCV for your car and see if it fixes it once it running lol.

Have you checked your cam phase adjustment since your rebuild?


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[NitroViper]

Have you checked your cam phase adjustment since your rebuild?


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Check it for what? chain stretch?

[JLAllroad]

Check it for what? chain stretch?

Check to see if the numbers are inline with a new timing system.

If nothing else it will give you a baseline to compare against as you add miles.


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[dalmation53]

Mine did have it's original PCV Valve and it's still working. i changed it for preventative maintenance and still does it. so That answers your question.
Ok since I bought the HPFP it's your turn to buy the original PCV for your car and see if it fixes it once it running lol.

[NitroViper]

Check to see if the numbers are inline with a new timing system.

If nothing else it will give you a baseline to compare against as you add miles.


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What are you saying tho? You think thats causing a rough start?

[Spawne32]

What are you saying tho? You think thats causing a rough start?

So many things on this car can cause a rough start its hard to pinpoint an exact one, you gotta look at everything. lol

[NitroViper]

So many things on this car can cause a rough start its hard to pinpoint an exact one, you gotta look at everything. lol

I dont know if I can check that with OBDeleven but if its stretched already then nothing I can do about it haha.

[Spawne32]

I dont know if I can check that with OBDeleven but if its stretched already then nothing I can do about it haha.

You can, I was the one who invented it. :p When you go into live data looking for camshaft related stuff, one of them is phase angle.

[NitroViper]

You can, I was the one who invented it. :p When you go into live data looking for camshaft related stuff, one of them is phase angle.

lol cool. Ill check that in a little while. Can you invent a 2 stage rev limiter code in there for me as well? I wanna brake boost to 32-3500rpm's lol.

[Spawne32]

lol cool. Ill check that in a little while. Can you invent a 2 stage rev limiter in there for me as well? I wanna brake boost to 32-3500rpm's lol.


If you have an IE tune your rev limit should be maxed. lol Problem is there is no such thing as launch control on an automatic, all your doing is brake boosting. Which is a good way to blow a torque converter up.

[NitroViper]

If you have an IE tune your rev limit should be maxed. lol Problem is there is no such thing as launch control on an automatic, all your doing is brake boosting. Which is a good way to blow a torque converter up.

I guess we shouldn't change the subject but ive brake boosted every automatic car I ever owned and Ive never blew a TC. Unless this car is a known weak spot and have failed. Lots of tunes have a 2 step rev limiter and its not like you do it every take off lol. People do it all the time at the drag strips.

[JLAllroad]

If you have an IE tune your rev limit should be maxed. lol Problem is there is no such thing as launch control on an automatic, all your doing is brake boosting. Which is a good way to blow a torque converter up.


Idk about the ZF6 but the ZF8 has AMAX launch AND shift program stock. HPTUNER can adjust the ZF8.

My 60ft without AMAX is ~2.2, and with AMAX 1.84-1.91, it will spin all 4 on dry pavement and a solid chirp on a prepared surface.

Run#3, APR stg2, AMAX (3100rpm), 8800DA, ~4200lbs, kids excited [emoji12].

https://youtu.be/kIk0rpSzkvI
193726


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[NitroViper]

Idk about the ZF6 but the ZF8 has AMAX launch AND shift program stock. HPTUNER can adjust the ZF8.

My 60ft without AMAX is ~2.2, and with AMAX 1.84-1.91, it will spin all 4 on dry pavement and a solid chirp on a prepared surface.

Run#3, APR stg2, AMAX (3100rpm), 8800DA, ~4200lbs, kids excited [emoji12].

https://youtu.be/kIk0rpSzkvI
193726


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What is AMAX launch? You're saying IE could adjust my RPM's? Spinning 4 tires would be awesome.

Ok now we are way off topic haha.

[Spawne32]

What is AMAX launch? You're saying IE could adjust my RPM's? Spinning 4 tires would be awesome.

Ok now we are way off topic haha.

AMAX is basically a half assed launch control system. It basically just allows you to briefly engage a set of maps that have higher shift pressure settings. It's still brake boosting the torque converter. Automatics don't work in such a way where you can disconnect the torque converter from the engine and "launch" like you can with a manual transmission. The advantage of getting into AMAX is that you get the benefit of those maxed out settings for the transmission. However if you can tune the trans, you can do that without the need to engage AMAX every time.

[Spawne32]

Idk about the ZF6 but the ZF8 has AMAX launch AND shift program stock. HPTUNER can adjust the ZF8.

My 60ft without AMAX is ~2.2, and with AMAX 1.84-1.91, it will spin all 4 on dry pavement and a solid chirp on a prepared surface.

Run#3, APR stg2, AMAX (3100rpm), 8800DA, ~4200lbs, kids excited [emoji12].

https://youtu.be/kIk0rpSzkvI
193726


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lol I had a 1.8 - 1.9 60 ft without AMAX :p 2.2 60fts are FWD times man, you gotta practice more. lol

[JLAllroad]

lol I had a 1.8 - 1.9 60 ft without AMAX :p 2.2 60fts are FWD times man, you gotta practice more. lol

8800 DA, 4200lbs....20” all seasons.

My AMAX range is still within a tenth of the 3.0T cars at this track and quite a few K04 Dragy times at lower altitudes.

That said, try staging and leaving on green with a good RT when it takes 2.5-3.5 seconds to boost to over 3000 rpm. Look at the RT of Run #1, I started boosting on green and left at 3k.

I just want to get into the 13’s before I change this setup, need to wait for October for a 65 degree night. IAT at the line are rarely below 100, even with an hour between runs.

2.2 is stomp and go, thing is slow AF from a stop w/o AMAX.


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[Spawne32]

Do you live on mount everest? lol

[JLAllroad]

Do you live on mount everest? lol

Nope, just summer in Colorado, with a track carved into the side of the mountain.193744193745193746193747


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[Spawne32]

My neighbors went out there once and actually could feel the difference in how hard it was to breath. lol Guess when your used to 14ft above sea level you can tell when the air is thin. lol

[NitroViper]

14ft
Youre getting close to space... duh

[Spawne32]

Youre getting close to space... duh

Well duh, I am used to living on planet earth. :p

[Traptalk]

Interesting find today.

Doing my initial ecu read out with hp tuners and check the software version of my 2011 caeb

https://i.postimg.cc/9fWW2Tbd/AF5-C8262-6-FDD-4-ACA-87-F1-2-EDE0300-C7-EB.png

Isn’t that operating system version the same version as the updated PCV ecm flash?

So does that mean I can run the white top?

I have no idea if I have the updated seal or not but I know the piston/rings were done around 30k miles by original owner

[Smac770]

Assuming the software is pulling that from your ECM and not assuming your ECM should be that (unlikely, but all possibilities must always be considered).
Yes, it would seem you should be running a white cap PCV. Are you not? By 30k, I assume you mean 30k ago? Did the owner do it themselves or have the dealership do it?

My assumption of the ECM software change is that it adapts to the change in air volume that would be ingested by the manifold unchecked by the throttle body. Black cap with less vacuum should pull less air through the breather valve from before the turbo. So if you had the white cap software, I assume the engine would have less air than expected and be rich on startup idle until closed loop. Do you run a negative idle trim?

So if you have a black cap, what block vacuum do you see at idle? I'm expecting .6 inHg.

As for the front main seal, you could validate it by removing the vibration damper and checking:

194257

[Traptalk]

Assuming the software is pulling that from your ECM and not assuming your ECM should be that (unlikely, but all possibilities must always be considered).
Yes, it would seem you should be running a white cap PCV. Are you not? By 30k, I assume you mean 30k ago? Did the owner do it themselves or have the dealership do it?

My assumption of the ECM software change is that it adapts to the change in air volume that would be ingested by the manifold unchecked by the throttle body. Black cap with less vacuum should pull less air through the breather valve from before the turbo. So if you had the white cap software, I assume the engine would have less air than expected and be rich on startup idle until closed loop. Do you run a negative idle trim?

So if you have a black cap, what block vacuum do you see at idle? I'm expecting .6 inHg.

As for the front main seal, you could validate it by removing the vibration damper and checking:

194257

Was done at 30k miles at the dealer. Car has 140k now

Been running a black top. Pretty sure it had one when I bought it but I can’t remember

[Smac770]

That's pretty bad to have needed it by 30k. But if it was done at 30k on an '11, it was almost certainly done at the dealership and paid for by AoA. They would have put a white cap on it. Doesn't mean someone at some point didn't put a black cap back on it, or use a third party unit that doesn't subscribe to the Audi black cap/white cap consideration.

But yeah, if it's had rings/pistons done, as expected with that software version, it would normally be running a white cap. But that you've not noticed any issue running a black cap with the white cap software is a data point to catalog.

[Traptalk]

That's pretty bad to have needed it by 30k. But if it was done at 30k on an '11, it was almost certainly done at the dealership and paid for by AoA. They would have put a white cap on it. Doesn't mean someone at some point didn't put a black cap back on it, or use a third party unit that doesn't subscribe to the Audi black cap/white cap consideration.

But yeah, if it's had rings/pistons done, as expected with that software version, it would normally be running a white cap. But that you've not noticed any issue running a black cap with the white cap software is a data point to catalog.

It appears in old photos it had a white cap. Not sure at what point it got switched to a black but that’s what I also got for Preventive maintenance a few months back.

Guess I gotta pick up white one

[Smac770]

If it's not having any issues, I wouldn't waste the money on the change. If I had to do something, I'd probably pick up that repair kit and just swap the spring. $14 sounds better than $140. Though I cannot say authoritatively that changes were not made to the hole or spring for the breather valve (the one on the bottom). But unless you have some issue you're chasing, I'm sure you've got better things to blow that coin on.
https://www.genuineaudiparts.com/oem-parts/audi-repair-kit-06h198542a

[NitroViper]

If it's not having any issues, I wouldn't waste the money on the change. If I had to do something, I'd probably pick up that repair kit and just swap the spring. $14 sounds better than $140. Though I cannot say authoritatively that changes were not made to the hole or spring for the breather valve (the one on the bottom). But unless you have some issue you're chasing, I'm sure you've got better things to blow that coin on.
https://www.genuineaudiparts.com/oem-parts/audi-repair-kit-06h198542a

Is that repair kit for the black top or white?

[Traptalk]

It’s also possible it’s causing some damage to seals I can’t really see.

I know at 108k the cylinder head was rebuilt and timing service performed. Thinking this is when it got changed to a black top. Maybe shop saw the 2011/2012 options saw my vehicular year and got the black cap. Was a independent shop not Audi dealer

At 140k and the cam position magnet is leaking a fair bit of oil again and possible the upper timing cover is too.

But I haven’t experienced drivability issues per say

My friends at the Audi dealership gonna run my vin and try to figure out if got the upgraded seal

[Smac770]

Is that repair kit for the black top or white?

It is for the white cap. It is not for the black cap. Per the TSB that introduced that repair kit.

Though if you use only the diaphragm and not the spring, I would imagine it would be fine for either. Just like the Dorman kit; you don't use the spring (because who knows what strength that spring is).

[NitroViper]

It is for the white cap. It is not for the black cap. Per the TSB that introduced that repair kit.

Though if you use only the diaphragm and not the spring, I would imagine it would be fine for either. Just like the Dorman kit; you don't use the spring (because who knows what strength that spring is).

Well I bought a $16 pcv to just try it for the start up issue, figured I could just throw a repair kit in the $16 PCV and have a OEM PCV for $30 lol... I dont see why that wouldn't work. It actually says delivered today so if its here ill take some pics of it.

[NitroViper]

This is the cheap $16 PCV from ebay.

https://cdn.discordapp.com/attachments/518596326900891648/749337413280727050/20200829_142514.jpg
https://cdn.discordapp.com/attachments/518596326900891648/749337414945734766/20200829_142523.jpg
https://cdn.discordapp.com/attachments/518596326900891648/749337415977533440/20200829_142533.jpg
https://cdn.discordapp.com/attachments/518596326900891648/749337416799748096/20200829_142542.jpg
https://cdn.discordapp.com/attachments/518596326900891648/749337418402103436/20200829_142625.jpg
https://cdn.discordapp.com/attachments/518596326900891648/749337420318638102/20200829_142733.jpg
https://cdn.discordapp.com/attachments/518596326900891648/749337420750913626/20200829_142643.jpg

[Spawne32]

https://media.giphy.com/media/8p05WdXxPiOyY/giphy.gif

[NitroViper]

looks EXACTLY like the one I took off originally.

[Spawne32]

Try it out, worst case scenario you need a rear main seal in the near future. lol

[NitroViper]

Try it out, worst case scenario you need a rear main seal in the near future. lol

Could say the same thing about my whole engine basically, it all came from china, every single part haha.

[NitroViper]

Im going to harborfreight and buy a vacuum tester, Im gunna test this white top OEM and test the ebay black top right after.

[Smac770]

06H 103 495B. Well, I guess we shouldn't be surprised that a part from China is a part only used for VAG China.
https://oemwolf.com/oem-parts/06h103495b.html
superseded by AB in '13. (our black cap history is A -> E -> AC -> AH)

https://audi.7zap.com/en/ca/audi+a4l/a4l/2009-669/1/103-103022/#16
So looks like they had B, replaced by K in Jun '12. Looks like K was superseded by AF in '13 (our white cap history is J -> AE -> AK)
I'm assuming the K->AF line is white cap.

Then you have things like AD, which was only for VW and apparently a black cap physically.

But there's no assurance of anything regarding engineering spec outside of the ones specifically for the same brand, same engine, same market, ie the US CAEB AH line (black cap) vs AK line (white cap). Any other market or engine could have any number of spec differences though it's the same physical housing. The leading way to test would be to take out the regulator valve spring and measure the height unloaded and with a a specific weight on it. Units with the same spring size and behavior should perform at the same spec, I would assume.

Or as Nitro is about to validate, the actual block vacuum at normal idle.

[Spawne32]

I have never seen a car over complicate a PCV system like this before...

[JLAllroad]

I have never seen a car over complicate a PCV system like this before...

They were trying to fix two things with a pcv without opening up and reengineering the engine, oil consumption (increasing the vacuum) and intake carbon (more velocity through the separator).....basically failed at both, still need rings and still have carbon build up.


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[NitroViper]

Here is the results of the vacuum tests. I dont see how it would ever be possible to blow the rear main with the black top. The vacuum is WAY less. I wish I had someone else's vacuum specs from another black top PCV. In the video you can see when I remove the gauge from the dipstick tube.

Wonder if this is going to mess with my k04 turbo tune.....



https://www.youtube.com/watch?v=frJvtU2lKvg

[JLAllroad]

Here is the results of the vacuum tests. I dont see how it would ever be possible to blow the rear main with the black top. The vacuum is WAY less. I wish I had someone else's vacuum specs from another black top PCV. In the video you can see when I remove the gauge from the dipstick tube.

Wonder if this is going to mess with my k04 turbo tune.....



https://www.youtube.com/watch?v=frJvtU2lKvg

Is that after the idle settles and w/o the AC on ?


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[NitroViper]

That is a warm/hot engine ac off.

[Smac770]

The black cap looks to be pretty much where I'd expect (.6 inHg), but the white cap seems lower than what I would expect (2 inHg vs. expected 3 inHg).
Blowing seals is not an issue when the PCV is fine. It's when the diaphragm tears and the regulating valve no longer regulates the vacuum passed through to the block (with the tear, there's no longer 14.7psi differential on the backside of the diaphragm pushing it to close down the valve passage). Then you get full manifold vacuum in the block, which is what does the number on the seals.