Fuel pressure too high... [Archive]

MmmBoost

03-20-2011, 07:22 PM

Finally got around to installing my inline fuel pressure gauge today, only to find out that my fuel pressure is NOT at all what I expected it to be. The 60 PSI Gauge was sitting around 50 psi after a key-on pump prime. Then when I started the car the gauge was pegged out at the pin below zero.

I just replaced my fuel filter and just got done confirming all of my lines are hooked up the right way.

Blue clip to RL
Black clip to VL
Evap hose to E
Fuel rail to MOTOR

Fuel pressure should be just below 4 bar from what i read......so I was expecting to see that. Anyone ever seen this before?? I'm thinking I got a bummed FPR in my filter.

MmmBoost

03-20-2011, 07:45 PM

The only thing I can think of is that the supply and return line are reversed. Why the hell would the color code be off?

A4 TSCHUSS

03-20-2011, 07:50 PM

58psi aka 4 bar is the stock pressure.

MmmBoost

03-20-2011, 08:01 PM

Exactly what I thought.

And I just got out from under the car. I disconnected what I was 100% sure was the pump supply line and stuffed the end into an empty water bottle. Then I turned the key on for a prime pulse and sure enough....the bottle has gasoline in it. So the filter is indeed hooked up correctly.

The FPR in the filter must be defective.

AudiA4_20T

03-20-2011, 08:25 PM

wait, so it was at 50? (a little lower than normal but nothing I would be worried about, could be the gauge) and then it's at 0? The car wouldn't start if it was at 0 obviously. I'm confused

MmmBoost

03-20-2011, 08:29 PM

No no .......

The gauge when I bought it was at 0. After I installed it and turned the key on for a priming pulse only the gauge was at 50 PSI. After I started the car, the gauge then went past 50, past 60, all the way around until it hit the stop at 0.

I hooked up another gauge and it was fluttering around 70-80 psi.

Ori0n

03-20-2011, 08:31 PM

Wuff. I'd try another gauge first, before jumping to conclusions.

MmmBoost

03-20-2011, 08:34 PM

I tried a 0-100 gauge AND a 0-60. Conclusion jumping is not something I do

Ori0n

03-20-2011, 08:36 PM

Now that I think about it, it does seem weird with just the key-on that it reads about right.

MmmBoost

03-21-2011, 07:14 AM

I should have got the gauge installed before I changed fuel pumps. I can't help but wonder if it has something to do with me installing 034's high-output pump on Friday.

Anyone else running the 034 005 pump had any issues like this? Maybe I even pinched the return line or something while re-installing the pump. Ideas?

heywier427

03-21-2011, 07:45 AM

does 034 list an operating pessure?

you cant run the same amount of fuel through the same diameter line without bumping the psi, so maybe its were its supposed to be.

give em a call.

good luck.

dirtybrd

03-21-2011, 08:14 AM

Extra pressure isnt a bad thing and I wouldnt be concerned on bit.

MmmBoost

03-21-2011, 08:20 AM

does 034 list an operating pessure?

you cant run the same amount of fuel through the same diameter line without bumping the psi, so maybe its were its supposed to be.

give em a call.

good luck.

I emailed 034 this morning. Waiting to hear back from them.....

Extra pressure isnt a bad thing and I wouldnt be concerned on bit.

Unregulated pressure is a bad thing. It's fucking my fuel trims up. It's making my idle shitty with 750cc injectors that used to purr like a kitten.

Dan[FN]6262

03-21-2011, 08:22 AM

its just trying to tell you to turn up the boost...

dougyfresh

03-21-2011, 08:39 AM

Extra pressure isnt a bad thing and I wouldnt be concerned on bit.

It'll affect the injectors since the duty cycle is designed to work on a given static pressure.

Chris,
Where in the fuel system did you hook the gauge up? You should be most concerned with pressure right at the fuel rail on the engine.

Did you calibrate the gage on a known pressure source first to ensure you are reading the right pressure? I had this problem when reading oil pressure as the gauge I purchased was way out of calibration thus throwing off my readings of oil pressure.

MmmBoost

03-21-2011, 08:45 AM

I hooked the gauge up right at the transition from hardline to rubber line on the firewall in the engine bay.

I didn't calibrate the gauge since it's brand new. But as I mentioned before......I tried two gauges. The 0-100 gauge was indicated erratic pressure between 70 and 80 PSI and the 0-60 was off the scale.

It's not the gauges. 2 different gauges can't possibly 25% out of calibration.

A4 TSCHUSS

03-21-2011, 09:05 AM

You wouldn't have touched te return line while installing a fuel pump, so don't see how you could have pinched a line so I would rule that out. The return line comes from the filter then up the front of the tank on passenger side to the top then shoots across to the drivers side and connects to the cap over there.

AudiA4_20T

03-21-2011, 09:08 AM

btw the fuel pump isn't the problem, you're right it would be something in the regulator. Fuel pumps will run at whatever they can, the regulator is what keeps pressure in check

MmmBoost

03-21-2011, 09:09 AM

What's the second line on the top of the fuel filter cap then? With the black plastic tube that goes down below the fluid level in the tank.

Top right
http://www.a4mods.com/pics/fuelpump/pic9.jpg

MmmBoost

03-21-2011, 09:11 AM

btw the fuel pump isn't the problem, you're right it would be something in the regulator. Fuel pumps will run at whatever they can, the regulator is what keeps pressure in check

Well i was just wondering if i may have kinked the return or something causing pressure to build up past the regulators setting.

Bische

03-21-2011, 09:29 AM

What's the second line on the top of the fuel filter cap then? With the black plastic tube that goes down below the fluid level in the tank.

Top right
http://www.a4mods.com/pics/fuelpump/pic9.jpg

I dont even have the line your mentioning, i dont have the small electric connector either. I had to plug that nipple when i changed my pump, the old one didnt have the nipple

diagnosticator

03-21-2011, 10:25 AM

The fuel pressure regulator in the filter, is calibrated to provide the correct fuel pressure with the stock fuel pump. Since you are now running a higher flow rate pump, the regulator can't flow enough bypass fuel to regulate the fuel pressure to 4 bar as before. With the regulator bypass back to the tank, at the 100 percent flow rate, the high flow fuel pump exceeds the capacity of the regulator control range bypass flow rate. Therefore, the fuel pressure will by unsteady and at a higher average pressure and flow rate with the high flow pump, compared to the stock pump.
As you already realize, the higher fuel pressure results in higher fuel flow rate from the injectors, directly effecting air/fuel mixture ratios. Consequently, one way to restore correct fuel pressure while still allowing for higher fuel flow when required, is to install a second adjustable inline fuel pressure regulator that is installed in parallel with the stock in-filter regulator. Adjusting the set point of the second regulator, the combined bypass fuel return flow rate of both regulators will reduce the in-filter regulator bypass return flow to less than 100 percent, restoring correct fuel pressure control.

Edit added:
The second regulator is connected with the inlet port connected to the fuel pump outlet line to the fuel filter inlet port and the regulator outlet port connected to the fuel return line back to the tank used by the in-filter regulator. Alternatively, run a dedicated fuel return line from the second regulator, back to the tank with a through wall fitting installed at the access cover at the fuel pump side of the tank, with the return line extended inside the tank to near the bottom.
A local pressure gauge is not required. Adjust the second regulator until the fuel pressure on the existing gauge shows the specified fuel pressure of 4 Bar, 58 psig.

Wet0willy01

03-21-2011, 10:40 AM

Install parallel? Wouldn't that allow for unfiltered fuel to see the engine/injectors? Do you mean in series?

Edit- I guess you attach a gauge to the outlet side and never see any flow out of the regulator into the fuel line, yet still regulate pressure and provide the additional path of return flow.

MmmBoost

03-21-2011, 10:41 AM

Thank you for the insight, diagnosticator.

I was thinking that the problem had to do with the increased flow from the new pump. the 005 is MUCH larger than the stock pump and after cutting open my old FPR to see how the regulator works, I was almost certain the issue had to do with the increased flow.

I'll see what 034 has to say about this considering there is ZERO mention that it may affect fuel pressure

diagnosticator

03-21-2011, 10:52 AM

Install parallel? Wouldn't that allow for unfiltered fuel to see the engine/injectors? Do you mean in series?

That is a good point, but no, not in series. The second regulator in parallel, will only return fuel to the tank via the same fuel return line used by the in-filter regulator. It won't send any fuel to the engine fuel rail.

MmmBoost

03-21-2011, 10:55 AM

I think I'm just going to have to redo the fuel system right from the pump. I was hoping I wouldn't have to do this.......but it looks like i need to get out my wallet again.

diagnosticator

03-21-2011, 11:12 AM

What's the second line on the top of the fuel filter cap then? With the black plastic tube that goes down below the fluid level in the tank.
Top right

The total return fuel is split into two flow streams, one goes to the suction jet pump at the fuel pump baffle housing, the second is sent to the left side of the tank to the suction jet pump in the left section of the tank, to transfer fuel across the hump in the tank back to the pump baffle housing in the right side of the tank.

MmmBoost

03-21-2011, 11:43 AM

I guess I'll use the stock supply line as my return line and run an Aeromotive or Fuelab regulator after the rail. I'll leave the manifold reference line unhooked until Tapp can find the other map I asked him for which is the "switch" for return/returnless.

Are the B5 guys having similar issues using the OEM regulator on the rail?

diagnosticator

03-21-2011, 11:50 AM

Yeah, that is another way to go, but remember that the reason for the returnless fuel system used on the B6 is to avoid heating the fuel in the tank from the warm/hot fuel returned from the regulator at the fuel rail back to the tank.

MmmBoost

03-21-2011, 11:56 AM

Yeah this is true, but there is nowhere to run another regulator and filter in parallel like you suggest. Space is TIGHT down there and those OEM plastic hoses and fittings do not make re-routing things easy.

Either way there is still heat being added to the fuel tank. The nature of the fuel being run through any regulator will cause heat to be introduced into the fuel. And even though the system is called "returnless" .....it still has a return—just not from the rail. It's not like the old carburetor fuel pressure regulators that are dead-headed and then cause the pump to heat up......but they only had to dish out 3PSI and enough fuel to fill up a float bowl.

At the end of the day......if warm gas in the tank is a necessary consequence of making this system work and meet the demands of the turbo/engine, then so be it. I could throw on an inline cooler on the return line to minimize the effect.

dougyfresh

03-21-2011, 01:44 PM

I think I'm just going to have to redo the fuel system right from the pump. I was hoping I wouldn't have to do this.......but it looks like i need to get out my wallet again.

You shouldnt have to do that. Others are running high flow pumps and everything is fine.

MmmBoost

03-21-2011, 01:47 PM

Have others check their fuel pressure after installing it?

I know David was experimenting with the Eurocode pumps......but i don't know all of the specifics of his fuel system.

I know he's on a return system now.

dougyfresh

03-21-2011, 01:51 PM

Yes.

Me.

I forget the absolute values but recall all was within spec. We had a gauge between the flexible line and the fuel rail. As close to the fuel rail as possible. It was plumbed into the dyno so we could log fuel pressure with RPM to make sure there was enough fuel. Fuel pressure barely moved near redline pushing about 400awhp. In tank Bosch 040.

dougyfresh

03-21-2011, 01:53 PM

I worked with ASP to do this because I wasn't sure where we'd run out of fuel and need bigger injectors or a bigger fuel rail (which we also designed but never cut chips). Turns out everything was okay. I still have a set of bigger injectors I had made but never used. Probably sell them when I get around to it.

MmmBoost

03-21-2011, 01:55 PM

Fair enough. I was just asking. Not a lot of people seem to want to mess with the fuel line.

Well wtf then....

034 still hasn't got back to my email yet. Awesome.

So Doug, you're on an 040 with an otherwise stock fuel system? Or..? Could you share a few more details, please?

A4 TSCHUSS

03-21-2011, 03:44 PM

Your aftermarket pump will not increase your pressure. Like Doug said his didn't change and neither did mine. I ran a fuel pressure gauge on the stock fuel system with a Bosch 040 fuel pump and the car ran at 58psi at idle or cruising and would drop a few psi to around 55psi under boost.

Here is a video that shows me under boost and then you can see when I let off the gas right at the end where it goes back to 58psi where it was while cruising before I started ripping gears. That was before I changed to the return style system so everything stock other than the 040 pump in the tank. No theories going on here, just actual texting. I made 392whp on a dyno dynamics at that setting with the boost tapering down to 26psi right at my peak so over 400whp anywhere else I would have dynoed and I am sure slightly higher if the car would have held the 28psi all the way out.

http://www.youtube.com/watch?v=DlO7SaQhlVE

MmmBoost

03-21-2011, 03:54 PM

So it must just be a defective FPR then.

LOL! The conversation at the parts desk at the dealership is going to be interesting. I only bought a new filter 1 month ago......and I'm not paying $68 for a new one.

Me: "So.....my fuel pressure is way above spec after changing my fuel filter last month"

Them: "Well maybe you need a new fuel pressure regulator"

"My fuel pressure regulator is in my filter"

"Your what is what?"

"Come out and have a look at the gauge after i start my car.....I want a replacement filter"

"Sorry we can't exchange used parts"

"How was I supposed to know it was defective before I installed it"

"Not my problem. There's 3 new ones in stock though. $68 each"

{facepalm}

A4SoftWalker

03-21-2011, 04:03 PM

Stupid parts guy didn't ans the question.

U needed a replacement for a DEFECTIVE part which was found to be defective by using it.

Dealer will warranty their parts and labor one year 15k miles. It might be optional if they are owner installed not sure of their policy.

MmmBoost

03-21-2011, 04:07 PM

it was a hypothetical scenario.

I have some checking to do tonight before I go to the dealer for a replacement.

diagnosticator

03-21-2011, 04:15 PM

I think teeing into the two lines near the fuel filter should provide enough room. The regulator itself can be nearby were it fits and is protected from the elements more or less. It does not need to be located at the fuel filter. A small inline plastic mesh type filter screen for the fuel flowing to the second regulator would be a good thing, but if there is no room, then it can be left out without major consequence.

The main consequence of warm fuel in the tank, is increased fuel evaporation rate. If the EVAP Purge fuel vapor recovery equipment is working right, then the recovered and stored fuel vapors will be burned up in the engine, and won't be wasted escaping to the outside air.

MmmBoost

03-21-2011, 04:59 PM

Well now that I'm home work i'm going to do some investigating.

First thing going to try is disconnect the fuel filter RL and hook up the barb from the filter to a hose and run it to a container, then check idle fuel pressure. The results of that test will determine what I check next.

I'll keep you guys posted on my findings. Thank you all for your suggestions/help/advice.

MmmBoost

03-21-2011, 05:55 PM

Disconnected the return line from the filter and hooked up some hose from the filter to a container.....started her up......still has the gauge pegged out and the container filled up so fast after 15 seconds of running i had to sprint to turn the key off. So the problem is clearly not the return line being kinked or blocked.

Edit: Added photos...and new conclusion. After shutting the car off, the pressure was at exactly 58 PSI. So it's clear to me that the regulator is holding the correct amount of pressure, it's just being overwhelmed by the flow.

So just in case some of you may be wondering what the FPR in the filter is all about. Here's a cut-away of my old fuel filter. This is the top with the regulator.

http://chrispaltzat.com/images/avant/build/oldfilter-01.jpg

http://chrispaltzat.com/images/avant/build/oldfilter-02.jpg

A4 TSCHUSS

03-22-2011, 09:08 AM

Explain why myself and Doug both had perfect pressure with performance pumps? Pump is not the problem. And I encourage anyone else running a performance pump to quickly hook a gauge to the back of your fuel rail if you have access to one and report back.

MmmBoost

03-22-2011, 09:26 AM

Explain why I'm having a problem.

I don't get it......I really don't. But I don't want to waste $70 on another new filter just to have the same problem

Hansi

03-22-2011, 10:15 AM

Maybe the 005 is flowing slightly more than the 040, causing the problem with the FPR?

I have seen a graph somewhere showing the 005 flowing more than the 040.

dougyfresh

03-22-2011, 10:20 AM

Maybe the 005 is flowing slightly more than the 040, causing the problem with the FPR?

I have seen a graph somewhere showing the 005 flowing more than the 040.

I think it does flow more but David was also using a pump that flows even more than the 040 and 005 and still didn't have any issues.

Chris, the easiest thing to do (that doesn't cost any money) is put your stock pump back in and see happens.

Hansi

03-22-2011, 10:24 AM

MmmBoost

03-22-2011, 10:28 AM

034's site says the 005 flows more than the 040.

I haven't been able to find much data on the 040 since it has apparently been discontinued......but i didn't come across this

(not that I put a lot of faith in the data)

https://secure.memca.com/ecodetuning/images/products/1894_large3.bmp

MmmBoost

03-22-2011, 10:50 AM

And more data....

So it's pretty clear that the 005 flows more than the 040

http://www.turbobuick.com/forums/attachments/e85-technical-forum/111352d1286053037-bosch-044-custom-install-great-e85-bosch-044-vs-040-vs-05-walbro-255.jpg

MmmBoost

03-22-2011, 11:46 AM

I think it does flow more but David was also using a pump that flows even more than the 040 and 005 and still didn't have any issues.

David is also on a return fuel system now. So I don't know what FPR and filter setup he's using. If it isn't the same filter, the pump he is using is irrelevant.

Chris, the easiest thing to do (that doesn't cost any money) is put your stock pump back in and see happens.

Going to rig up the old pump tonight and see what happens.

dougyfresh

03-22-2011, 02:34 PM

And more data....

So it's pretty clear that the 005 flows more than the 040

Yes, supposedly the 005 flows more.

There was a huge restriction on the 040 that 034 used to sell.... the banjo the fuel line connects to. The ID of the barb on the banjo was waay too small for its purpose. Last winter ('09) I installed a much larger banjo on my 040 and a large fuel line so the IDs are pretty consistent and there are no more bottlenecks.

I am not sure if those flow tests include the effects of the supplied banjos on the fuel line fitting of the pumps. If they do then there is more potential to the 040 than that chart shows.

When you pull the pump, can you measure the ID of the banjo barb fitting on your 005 please (in mm)?

A4 TSCHUSS

03-22-2011, 02:56 PM

dougyfresh, are you sure he did the test with the 044? From this quote it looks to be with the 040..

Actually that was a mistake, I had the Eurocode XXX pump in the car. I had just installed it about 3 months prior when I was testing a "Eurocode Revo" file and took the 040 out at the same time since I was advised it wouldn't be good enough (which isn't the case).

I think it does flow more but David was also using a pump that flows even more than the 040 and 005 and still didn't have any issues.

This is correct, Eurocode XXX pump was in the car which is shown to be the highest flowing pump on that first graph posted and I had a perfect 58psi pressure with all stock fuel system.

MmmBoost

03-22-2011, 03:00 PM

Actually that was a mistake, I had the Eurocode XXX pump in the car. I had just installed it about 3 months prior when I was testing a "Eurocode Revo" file and took the 040 out at the same time since I was advised it wouldn't be good enough (which isn't the case).

This is correct, Eurocode XXX pump was in the car which is shown to be the highest flowing pump on that first graph posted and I had a perfect 58psi pressure with all stock fuel system.

Were you running an OEM filter? or another manufacturer? I wonder if there are differences between them in terms of flow capacity.

A4 TSCHUSS

03-22-2011, 03:30 PM

I have no idea what brand it was, think I bought a replacement filter from ecs tuning when I did change my filter previously.

EDIT: Here it is, when I switched to the "return system" I took the old filter out and cut it in half. Looks like OEM to me.

http://i8.photobucket.com/albums/a48/Urbamworm/134-3423_IMG.jpg
http://i8.photobucket.com/albums/a48/Urbamworm/134-3424_IMG.jpg
http://i8.photobucket.com/albums/a48/Urbamworm/134-3425_IMG.jpg

dougyfresh

03-22-2011, 04:37 PM

I typically get my filters from germanautoparts.com (http://www.germanautoparts.com/Audi/A4/Fuel/92/6).

I replaced my filter in CO last summer as the pump was quite loud when up at 12+kft. I thought my filter might have been clogging up as it did have over 30kmiles on it. Jordan picked it up for me at his dealership. A genuine bosch unit.

MmmBoost

03-22-2011, 04:48 PM

My new one is a brand new one right from the dealer. Bought it Feb 18th and installed it that night.

AudiA4_20T

03-22-2011, 04:52 PM

MmmBoost

03-22-2011, 05:01 PM

I feel like something about the gauge is off. We have done testing at the shop on stock cars and my car with the in-line pump and have had consistent pressure. If your FPR is good everything should work fine

From an earlier post....

I hooked the gauge up right at the transition from hardline to rubber line on the firewall in the engine bay.

I didn't calibrate the gauge since it's brand new. But as I mentioned before......I tried two gauges. The 0-100 gauge indicated erratic pressure between 70 and 80 PSI and the 0-60 was off the scale.

It's not the gauges. 2 different gauges can't possibly 25% out of calibration.

By the way both were brand new. In fact I had the 0-100 PSI 034 Motorsports gauge on there first and took it off because i thought the gauge was messed up since the needle was jumping around all over the place instead of rock solid at 58.

EDIT: More photos of the stock regulator for the curious type.

http://chrispaltzat.com/images/avant/build/oldfilter-03.jpg

http://chrispaltzat.com/images/avant/build/oldfilter-04.jpg

http://chrispaltzat.com/images/avant/build/oldfilter-05.jpg

http://chrispaltzat.com/images/avant/build/oldfilter-06.jpg

http://chrispaltzat.com/images/avant/build/oldfilter-07.jpg

http://chrispaltzat.com/images/avant/build/oldfilter-08.jpg

dougyfresh

03-22-2011, 06:17 PM

you are canadian. what are you doing measuring in English units?

Only us morons in the US do that [:D]

MmmBoost

03-22-2011, 06:59 PM

I didn't want you guys to have to do the conversions. You'd screw something up :P

The test results are in! ........just compiling the data.

........btw Doug, the ID on the banjo fitting on my 005 is 5mm

A4 TSCHUSS

03-22-2011, 07:04 PM

Which is the baby outlet that comes on the 040 pumps, surprised they put that on the newer "higher flowing" pumps as well. When I switched from the 040 (which had that tiny connection to the XXX it had a bigger banjo on it which was 3/8" outer diameter, not sure what the inner would be but you could probably stick the 040 banjo inside of it.

dougyfresh

03-22-2011, 07:35 PM

........btw Doug, the ID on the banjo fitting on my 005 is 5mm

One that came with my 040 pump on left. The one I bought to better match the fuel line on the right.
http://farm6.static.flickr.com/5255/5552090772_0776267b65.jpg

http://farm6.static.flickr.com/5141/5552091110_8d77524ae8.jpg

http://farm6.static.flickr.com/5134/5551504403_5ecdfe3eb6.jpg

its the little things that make it or break it...

MmmBoost

03-22-2011, 07:35 PM

I've now switched pumps 3 times tonight. I haven't eaten dinner yet. And I smell like gasoline.

.......but I think it was worth it

First Test was with the 0-60 PSI Marshall gauge I have had on there since I removed after I first thought my 034 Marshall gauge was broken. I then switched back to the 0-100 034 gauge to show how it's reacting.

From the results of my testing it's pretty clear that the FPR can simply not keep up with the flow from the Bosch 005. It also shows that it's not my gauges....

Bosch 005 pump prime pulse
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-01.jpg

Bosch 005 pump @ idle
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-02.jpg

Stock VDO pump @ idle
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-03.jpg

Stock VDO pump @ idle
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-04.jpg

Bosch 005 pump @ idle
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-05.jpg

Bosch 005 pump @ idle with supply line loosened
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-06.jpg

dougyfresh

03-22-2011, 07:45 PM

I would conclude (without testing another FPR/filter) that your current FPR is suspect. Not that the FPR can't keep up with the higher flowing pump. There is still an unknown in your equations.

MmmBoost

03-22-2011, 07:50 PM

I would conclude (without testing another FPR/filter) that your current FPR is suspect. Not that the FPR can't keep up with the higher flowing pump. There is still an unknown in your equations.

Unfortunately I don't have another FPR to test. And after the results of the tests, I'm not sure I want to waste my money on buying another one. I can't get a filter cheaper than $70 in town, and by the time I order one it'll be $70 with shipping at taxes. I could put that toward an external FPR that I know will work. Even if it is this particular FPR........if it happened once, that means it can happen again.

It seems pretty strange than the 005 was able to come very close to normal operating pressure when the supply hose was loosened and allowed to leak.

Oh, and my banjo fitting is not an off the shelf item. It is machined. The ID is 5.0mm

A4 TSCHUSS

03-22-2011, 08:03 PM

That is weird, I am still not buying that is the pump flowing to high for stock regulator though, going back to I had a higher flowing pump than you and it was perfect, Clint had an inline pump the was higher flowing and his was perfect and Doug has the 040 which flows more than stock and it is perfect, there has to be something wrong with your regulator in that filter.

Maybe invite a friend over and swap their filter in real quick so you don't have to buy one to test it?

MmmBoost

03-22-2011, 08:20 PM

I have managed to bamboozle 2 filters to try out this week. A brand new OEM never been installed. And a used one from a car my friend is parting out.

......the plot thickens

Dan[FN]6262

03-23-2011, 04:49 AM

good luck.

diagnosticator

03-23-2011, 05:31 AM

I have managed to bamboozle 2 filters to try out this week. A brand new OEM never been installed. And a used one from a car my friend is parting out.

......the plot thickens

Testing for more information is worthwhile here, but since the in-filter regulator is controlling fuel pressure at the specified 58 psig, when the stock pump is operating, and when you loosen the fuel discharge line at the filter, it is practically certain the in-filter fuel pressure regulator is not somehow defective, and is instead a case of the regulator bypass maximum flow rate capacity being 100% open when the Bosch 005 pump is operating. It's clear the in-filter regulator is unable to control fuel pressure with the regulator bypass open 100%, and any increase of fuel pump flow rate will then increase the fuel pressure higher than the specified 58 psig. All the relevant evidence supports this as the cause of why the fuel pressure is excessive by at least 10+ psig, or higher.

MmmBoost

03-23-2011, 08:43 AM

Testing for more information is worthwhile here, but since the in-filter regulator is controlling fuel pressure at the specified 58 psig, when the stock pump is operating, and when you loosen the fuel discharge line at the filter, it is practically certain the in-filter fuel pressure regulator is not somehow defective, and is instead a case of the regulator bypass maximum flow rate capacity being 100% open when the Bosch 005 pump is operating. It's clear the in-filter regulator is unable to control fuel pressure with the regulator bypass open 100%, and any increase of fuel pump flow rate will then increase the fuel pressure higher than the specified 58 psig. All the relevant evidence supports this as the cause of why the fuel pressure is excessive by at least 10+ psig, or higher.

Things certainly are pointing in that direction, John. If I can get hold of that brand new filter from a friend today that will be the nail in the coffin for me.

.....I have already started planning out my new fueling setup in the meantime, as I expect that this other OEM filter will have identical results.

MmmBoost

03-23-2011, 10:17 AM

As per Javad @ 034 regarding the email I sent....

So the pump is flowing too much? LOL, I've certainly never seen this, this pump has been installed in hundreds of B6's exactly like his, this is a known working installation. Only thing I can think of is that his regulator is bad or the return from the filter to the tank is kinked or blocked somehow, but the 005 pump does not outflow the stock regulator, I can assure that.

dougyfresh

03-23-2011, 10:30 AM

Time to test a new filter/FPR

MmmBoost

03-23-2011, 10:48 AM

Looks like that's the case.

We shall see what happens this evening if I can find some time to do some testing

M-Hood

03-23-2011, 12:33 PM

Just sounds like the FPR is not opening 100% to allow enough flow thru when running the 005 pump, but opens enough to hold the correct pressure with the stock pump.

MmmBoost

03-23-2011, 04:59 PM

Time for the final test.....

I managed to get a brand new filter in town for a decent price. I shall report back shortly with my findings.

http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-01.jpg

http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-02.jpg

http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-03.jpg

http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-04.jpg

http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-05.jpg

MmmBoost

03-23-2011, 06:12 PM

New filter in and completely hooked up. ZERO change in the outcome. Bouncing like crazy between 70 and 80PSI at startup and finally levels out at about 72 PSI when fast idle tapers off.

I even went so far as to disconnect the vent line thinking it might be the culprit

And to prove it is not the return line that is causing a restriction..........again I hooked up a rubber hose off of the filter return port and dumped it to a container.

ZERO change in the outcome.

......and then for shits and giggles I decided to disconnect both the supply and return lines and dump them into water bottles just to be sure I'm not going crazy and have the lines hooked up the right way. After a prime pulse.....my "supply" line is actually my supply......the same results as my previous test yesterday.

So I believe that I have proved beyond a shadow of a doubt that it is indeed a matter of too much flow and not a coincidence that I got a defective fuel pressure regulator. If anyone would like to tell me otherwise I would REALLY like you to explain why. Short of hooking up a pressure gauge right off of the filter dead-headed there is nothing more to prove. And even if I had a kinked of crushed supply line, pressure downstream of the restriction would have less pressure.

Idle fuel pressure with brand new OEM Filter installed and completely hooked up
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-06.jpg

Hose off of the return port dumped to a container
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-07.jpg

The hose on the return port
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-08.jpg

Idle fuel pressure with return line dumped
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-09.jpg

The amount of fuel that should have returned to the tank from the time it took me to start the car....quickly snap a photo....and shut the car off.
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-10.jpg

The resulted of my just to confirm I'm not going crazy test. (the one with the most fuel is the black connector which hooks to VL)
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new filter-11.jpg

A4 TSCHUSS

03-23-2011, 06:16 PM

I honestly don't know what to say other than what Javad told you, out of "hundreds of B6s" with me included in there with a higher flowing pump, you seem to be the only one having some kind of voodoo going on. I don't know how to explain it, but it is definitely very weird.

MmmBoost

03-23-2011, 06:37 PM

Trust me, David.....I'm just as speechless.

Looks like I'll be converting to a return system MUCH sooner than I expected.

20vturbo

03-23-2011, 07:09 PM

What's the second line on the top of the fuel filter cap then? With the black plastic tube that goes down below the fluid level in the tank.

Top right
http://www.a4mods.com/pics/fuelpump/pic9.jpg

the picture is wrong...what is marked as return is actually the vent that is connected to the fuel regulator...Be careful cuz if you connect the wrong hose there and plug the vent the regulator won't open and cause the pressure to increase

dougyfresh

03-23-2011, 07:51 PM

Looks like I'll be converting to a return system MUCH sooner than I expected.

Can you explain again what is driving you to worry about fuel pressure? You can't get the IDC to be consistent when tuning your car?

I honestly do not know what to say because there are many B6s out there with fuel injectors ranging from 440cc/min to 1000cc/min all running fuel pumps ranging from stock to large like an 044 and the IDC have been dialed in for the cars to idle perfectly with 14.7:1 AFR. Not sure why your car is an exception.

MmmBoost

03-23-2011, 07:55 PM

What is causing me to worry about fuel pressure is that it is not what it's supposed to be. If i'm running at 70 psi at idle and light cruise and I tune for that........what happens when I need more fuel on boost and fuel pressure drops to 58 PSI (because less fuel is required to be return) when my car is tuned for 70 psi? i'm going to be pretty short on fuel.....aren't i? And yes O2 corrections could probably compensate, but i'm sorry that's just not how I'm going to tune my car.

I have found the problem. I'm just compiling my photos right now. Will post up shortly.

It isn't my car that's the problem. ........it's the filters.

Doug, David......are/were you guys using a 3-port or a 4-port filter?

A4 TSCHUSS

03-23-2011, 07:58 PM

I posted a pic of my filter. It is a normal filter, the identical one that you have pictured.

dougyfresh

03-23-2011, 08:27 PM

pretty sure I'm using the 4 port. It looks identical to the one David posted (minus the AN fittings) and identical to the new OEM one you bought today.

there is a 3 port?

MmmBoost

03-23-2011, 08:31 PM

After being pretty frustrated with this whole situation, I was trying to figure out what the problem could be. I've had this half-cut-open fuel filter sitting on my desk for a month now and I never bothered to really look at anything other than the FPR side of things. Well after picking up the other half.....I was trying to figure out what the return port was all about.

.....after looking through the return port, I saw there was a TINY hole in the white tube pictured below. It was much smalled than the output ports and much smaller than the tube diameter....and it even looked smaller than the FPR outlet. The ports all measured 5mm ID and this hole in the white tube is probably 1.5-2mm in diameter. (it is impossible for me to measure without cutting the tube)

I figured this had to be the point of restriction that was causing the build up of pressure. Since I have 2 brand new filters, I figured I had nothing to lose by drilling this orifice out and throwing it on the car. So I drilled it out with a 3/16" dill bit, cleaned up the plastic chips as best as I could with a spiral brush, and then installed it on the car with the return port hooked to the infamous plastic container to flush out any remaining chips. Started the car up and let it idle.....and sure enough fuel pressure was pretty much normal.

So I reinstalled the tank return line and then started the car up again and let it idle until fast idle tapered off........what do you know..........58 PSI.

Exploded view of the filter
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new%20filter-12.jpg

The culprit
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new%20filter-13.jpg

ID comparison of return tube and return port
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new%20filter-14.jpg

ID of return port
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new%20filter-15.jpg

Diameter of drill used to "massage" the return tube
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new%20filter-16.jpg

SUCCESS!!!!!!!!!!!!!!!!!!!!!!!!!!!
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new%20filter-17.jpg

kwan

03-23-2011, 08:48 PM

wtf

MmmBoost

03-23-2011, 09:20 PM

wtf

I don't get it?

Anyway.....some of you may mention that the orifice is there for a reason, and I know that, but at this point I just want the problem solved. I'll do some testing this weekend with fuel pressure while driving and see how it responds. If the fuel pressure is a little jumpy, I still have another filter to experiment with. I'll try a smaller orifice size.

kwan

03-23-2011, 09:25 PM

You could always do a output measurement if you want to be sure (measure quantity of fuel per voltage/time applied). That pump must be flowing like crazy to be blowing by the fpr and bottlenecking at the white tube.

diagnosticator

03-23-2011, 11:36 PM

So the in-filter regulator was being flow limited by the 1.5/2mm orifice hole in the plastic tube, since the orifice is inline with the regulator inlet. I was not aware there was a plastic tube and orifice as part of the filter/regulator assembly. Regardless, the small orifice hole resulted in the same effect on fuel pressure vs. flow rate as if the regulator port itself was the limiting factor for the flow induced excess fuel pressure.

Good job finding that restriction, it is an obscure detail in the overall big picture here. It's also likely other users of high volume pumps have this problem with excess fuel pressure and don't even realize it is happening.

MmmBoost

03-23-2011, 11:50 PM

The orifice is on the tube that connects the regulator to the outlet port RL. So the restriction is actually after the regulator. ......but yes it was still causing the same effect.

Yeah it took a little work to get to the bottom of it, but i'm glad I was systematic about it. Eliminating the variables one by one. I'm just glad it only cost me $55 for a filter instead of $400 for a new return fuel setup and then HOURS trying to make the tune work.

I suspect that a number of people are in fact having this problem but don't know it. Perhaps 034 started supplying the 005 with a larger banjo fitting that was allowing just that little bit more flow to cause an issue? I have no idea. I also don't think that many people put a fuel pressure gauge on the line and check their pressure........especially when it's a "drop-in" solution.

In any case....I am ecstatic that I got to the bottom of it.

dougyfresh

03-24-2011, 03:38 AM

diagnosticator

03-24-2011, 05:36 AM

dougyfresh

03-24-2011, 06:01 AM

MmmBoost

03-24-2011, 08:05 AM

5mm is a larger banjo fitting? Its small. Besides, David and I (and a few others) don't have any problems with a banjo significantly larger than 5mm ID using OEM filters.

While your conclusions are tangible I still don't believe as to why we don't have this issue.

Perhaps the pump was being supplied with something like this.......
http://farm6.static.flickr.com/5141/5552091110_8d77524ae8.jpg

its the little things that make it or break it...

MmmBoost

03-24-2011, 08:13 AM

While your conclusions are tangible I still don't believe as to why we don't have this issue.

I don't know why you guys aren't having issues. I really can't explain it......nor am I going to try.

.......all i know is that after adjusting filter return my problem went away. I can't possibly be the ONLY person to have this problem with this filter and high-flow pump. ........but I'm going to say the reason I found I had a problem is because I am doing my own tuning and wanted to know EXACTLY what my fuel pressure was at the rail so I could put in the correct injector constant into my file.

M-Hood

03-24-2011, 09:40 AM

Could be that not all of the stock filters are the same specs, which wouldn't be a factor on a stock pump. Some people that never put a gauge on their fuel line when running a larger pump might never notice the issue, only thing that might pop up is high fuel correction numbers on block 032 even though the car runs perfectly normal.

Dan[FN]6262

03-24-2011, 10:20 AM

good find, very interesting [up]

cdn20valve

03-24-2011, 10:23 AM

Is this discovery an easy way to get more fuel out of a returnless system?

M-Hood

03-24-2011, 10:37 AM

Yes. The higher fuel pressure will basically make the injectors seem larger in CC, but higher pressure also means less flow. If your dont max out the pump the higher pressure can give you more head room for more power since the injectors are able to spray more fuel before you max out the injector.

-03 tq

03-24-2011, 04:00 PM

MmmBoost did you read this few days back? http://www.audizine.com/forum/showthread.php/401488-Fuel-problems-b6-BAT Shit, you Sir just saved me xxx euros not making me buy aftermarket fpr and hiflow filter. So this mod you discovered makes our pump flow more, right?

MmmBoost

03-24-2011, 04:29 PM

I didn't actually read that thread. Been pretty busy the last few days here trying to get my issues sorted out.

After going through the thread it seems like you're having a similar issue. At one point you said fuel pressure was at 5.5. Something very wrong there.

Drilling out the filter will not make the pump flow any more. It will make the fuel filter/FPR flow more.

Edit: You said that you hooked up the pump to an external regulator. Just on it's own? or through the system?

-03 tq

03-24-2011, 04:35 PM

Yes, but fuel flow to rail/injectors should be significally increased?

MmmBoost

03-24-2011, 04:44 PM

No. It will most likely solve your 5.5 bar fuel pressure problem at idle. It may fix your flow issue at the rail......but I don't know that for sure.

I was not trying to find a solution to a flow problem. I was trying to find out why fuel pressure was not what it was supposed to be.

I recommend that you try a solution like mine and go from there.

A4 TSCHUSS

03-24-2011, 06:14 PM

I think the reference to banjo fitting ID, is that the fitting used is larger than 5mm, that is how I interpret the situation anyway. There is nothing given to conclude that the fuel pressure is not being regulated properly on other high flow fuel pump setups, other than the assumption that if it's happening to other users, the excess fuel pressure has not been discovered by measurement or other means.
There seems to be at least several guys with ECUs tuned by different tuners, that have issues with excess fuel-rich air/fuel ratios, at idle and low loads, evidenced by maxed out fuel trim adaptation values that have tried the usual methods to correct the excess fuel problem, but without success.

There are several unique part numbers for fuel filters based on engine and model year. There may be differences between the in-filter fuel pressure regulators that are related to regulator flow capacity and pressure set point, with the different filter part numbers, but that is only a speculation on my part without more information. Especially when purchased aftermarket, it's likely some filters are sold for use with the wrong applications.

I am going to post all of this again since I think you somehow missed it? [confused]

I ran the XXX pump which as you see was one of a few tested pumps that Eurocode sold. And it was the highest flowing pump in their lineup, higher than the 005.

https://secure.memca.com/ecodetuning/images/products/1894_large3.bmp

I don't have a video of the car just sitting and ideling with the gauge installed but verified it without video. I do have this video where you see at around 11 seconds where it goes back to 58psi when I let off the gas after my pull. Perfect 58psi, I don't know how you couldn't conclude it wasn't being regulated properly when you can see with your own eyes 58psi in the video.

http://www.youtube.com/watch?v=DlO7SaQhlVE

The pump had a big outlet on it like this. I had an 040 pump which had the smaller sized outlet like on the left and then the XXX pump which had the bigger one like on the right and is the same one I now have on my 044 pump. It takes a 3/8" diameter fuel hose to go on it.

http://farm6.static.flickr.com/5255/5552090772_0776267b65.jpg
http://farm6.static.flickr.com/5134/5551504403_5ecdfe3eb6.jpg

And here is a crappy pic of the filter which is oem, you can sort of see the part number.

http://i8.photobucket.com/albums/a48/Urbamworm/134-3423_IMG.jpg

M-Hood

03-25-2011, 08:35 AM

Yes, but fuel flow to rail/injectors should be significally increased?

You have to look at how a pump flow is effected by the fuel pressure. The higher the pressure the lower the flow. This is why most tuners on the fuel return setup on the B5's kind of went away from using a 5 bar fpr vs the stock 4 bar and even went towards using a 3 bar. Higher pressure will increase your injector size and give you more head room for more fuel by the time the injectors max out, but your flow from the pump will be reduced.

diagnosticator

03-26-2011, 02:22 AM

David, I never said I doubted that your fuel pressure was correct. I did not miss your statements to that point. My comments are directed to the general perspective, speculating that since the overpressure occurred with this specific Bosch 005 and the stock filter/regulator, then it may be happening on other B6 A4s with the same setup. But if the overpressure is also happening on other 005 setups, it hasn't been discovered by those users yet, or made known on the forum if the users know of the issue, if the overpressure was occurring on those other installs of the 005 as well. Since there is nothing with Chris's setup that is unusual, it is more likely the overpressure is happening on other B6 installations also. The only thing that may be relevant, and I don't know if this is the case or not, is if the filter/regulator flow specifications are different between the filter PN versions, related to the presence or size of the orifice tube that is limiting the regulator bypass flow capacity and the associated pressure regulation capability with higher than stock flow rate pumps, specifically the Bosch 005 and the same PN filter-regulators used with that pump as shown here.

diagnosticator

03-26-2011, 02:46 AM

From 034's webpage:

"NOTE, drilling out the gas tank return on the fuel filter housing may be required, this is the center port on the side with 2 nipples, a 3/16" drill bit can be used to drill out a restrictor in the plastic, otherwise excessively high pressure can be seen at idle. Not all customers have reported this, but some have needed to do this."

http://www.034motorsport.com/fuel-injection-solutions-audi-a4-b5-b6-fuel-line-upgrade-kit-b6-audi-an-p-18675.html

A4 TSCHUSS

03-26-2011, 03:56 AM

They probably just added that since Javad's email showed they had never heard of this problem.

MmmBoost

03-26-2011, 12:30 PM

MmmBoost

03-27-2011, 07:21 PM

Just to let everyone know, the hole in the return tube is in fact 1.5mm. I have some 1.5mm solder laying around and out of curiosity, tried to see if the size was the same. Sure enough, I was just barely able slide the solder through the return tube on the filter I cut apart.

I'm thinking 3/16" (4.76mm) may have been too large of a hole to drill, So i'm going to start experimenting working my way up through the bits. I never used to get a pop when I blipped the throttle to rev-match on a downshift, now I do. And I'm getting some strange idle oscillations if I blip the throttle at idle a certain amount. They biggest challenge though, is reaching the orifice. The orifice is 52mm deep from the end of the return port and it's about 10mm long if i hold the white tube up to a bright light. Most drill bits that small are very short. The smallest bit I have with a long enough shank to be able to drill through the whole orifice is a #34 which measures 0.111" or 2.83mm.

I've been doing a little research and stumbled across this from an AEM FPR manual

A unique feature of the AEM adjustable pressure regulator is that the discharge port in the
regulator is changeable. This allows the user to tailor the regulator return volume to match their
fuel pump. A common problem that occurs when using a fixed orifice in a “universal” regulator is
that the fuel pressure cannot be effectively controlled when the fuel pump volume is significantly
higher than stock. In the case of too small of a discharge orifice, there is a large pressure spike
associated with rapid deceleration because the orifice cannot flow enough fuel when the
diaphragm is fully deflected to the open position. This causes a momentary rich condition, which
may lead to a rough idle quality until the pressure stabilizes. Conversely if the discharge orifice
is too large the adjustment is difficult because the response of the fuel flow out of the orifice is
too rapid which makes the adjustment screw too sensitive. The AEM regulator is packaged with
three orifice sizes, .100”, .150” and .200”.

But I don't know if any of this is going to make any difference since the orifice size on the ouput of the actual FPR inside the filter also appears to be 1.5mm

Dan[FN]6262

03-28-2011, 06:07 AM

hrrmmmmzzzzzz......

AudiA4_20T

03-28-2011, 06:18 AM

I just converted to return fueling for $30 and called it a day

dougyfresh

03-28-2011, 07:30 AM

Javad and I have been exchanging emails for the past couple days. He too was skeptical at first, but after sending him photos of all of the testing and describing the methods I used and what solved the problem, he became a believer.

He just added that note to the fuel pump and the fuel filter/-6 AN line kit.

Did he do any testing?

Before adding that blurb to their website I would go check a few B6s that are in the shop since this thread has at least two b6s without any issues and yours with supposed 'issues' sans modified fuel filter.

MmmBoost

03-28-2011, 07:35 AM

Did he do any testing?

Before adding that blurb to their website I would go check a few B6s that are in the shop since this thread has at least two b6s without any issues and yours with supposed 'issues' sans modified fuel filter.

He didn't do any testing, and I told him that 3/16" may not be the optimal size and that I wanted to do some testing, but he seemed to have his mind made up that that far away from the FPR would not have any effect.

My "supposed issues" ??? ......what exactly does that mean?

diagnosticator

03-29-2011, 07:41 AM

As far as tuning your ECU, I believe it is better to have a rising rate fuel pressure regulator, that allows setting the injector flow rate in the tuning program using a fixed value, instead of the ECU having to calculate the injector flow function based on the pressure difference between the fuel pressure and the manifold absolute pressure, as the MAP varies with engine load. The ECU makes this calc as required by the returnless fuel system. Maybe leaving that unchanged in the ECU is easier, but I am skeptical if it's a better method that having a fixed Delta P, MAP/Fuel pressure. Real measured values are almost always better than calculated values if the real values are known directly, without relying on inferences from indirectly related variables when they are not available measured directly.

MmmBoost

03-29-2011, 08:37 AM

I would like to convert to a return system with a rising rate.....if i was able to convert a while ago I could have kept my Genesis 550's that run flawlessly.

However, I do not have all of the tables available to convert just yet. I am able to access the map where the ECU compensates for fuel pressure-manifold pressure, but I don't have access to the toggle that actually switches between return and returnless. I've asked Tapp to find the block for me, but haven't heard from him in a couple weeks, so I just shot him an email to see where he's at.

At the very least I am thinking of converting to return and just leaving the FPR pressure reference port disconnected until he gives me access to all of the tables I need to actually uses the 1:1 ratio.

pape

07-02-2011, 01:51 AM

How did all this turn out?

It was a verry intresting thread. I have a 044 am going to install with the stock fuel system and came across this.

PG1.8T

07-02-2011, 02:11 PM

Last year my stock fuel pump failed and I replaced it with Audi B6 High Output Drop-In Fuel Pump, my car was stock at that time and I had exactly the same problem. Too much fuel and starting my car was a problem, I had black smoke out of exhaust and realy rough idel. I replaced filters 3 times with same result and than gave up. Replaced the pump again with OEM pump and everything is fantastic.
If you gona convert your car to a return fuel system please post pictures, I would like to do that too.
Good job on figuring out the problem.

MmmBoost

07-03-2011, 08:32 AM

How did all this turn out?

It was a verry intresting thread. I have a 044 am going to install with the stock fuel system and came across this.

How did all what turn out?

Last year my stock fuel pump failed and I replaced it with Audi B6 High Output Drop-In Fuel Pump, my car was stock at that time and I had exactly the same problem. Too much fuel and starting my car was a problem, I had black smoke out of exhaust and realy rough idel. I replaced filters 3 times with same result and than gave up. Replaced the pump again with OEM pump and everything is fantastic.
If you gona convert your car to a return fuel system please post pictures, I would like to do that too.
Good job on figuring out the problem.

Fuel System Upgrade/Return Fueling Upgrade (http://www.audizine.com/forum/showthread.php/366320-The-Build-A-GT2871R-build-documentary?p=6597277&viewfull=1#post6597277)

PG1.8T

07-03-2011, 11:25 AM

wow, nice pictures. Thank you.

pape

07-04-2011, 01:53 AM

How did all what turn out?

Fuel System Upgrade/Return Fueling Upgrade (http://www.audizine.com/forum/showthread.php/366320-The-Build-A-GT2871R-build-documentary?p=6597277&viewfull=1#post6597277)

I read over your other Thread. I see you ended up going return. But did you ever try difrent size holes on the filter with the returnless? when you used the 3/16 bit how did it work out? would you lose presure at high rpms?

mariosa4

07-04-2011, 04:39 AM

what filter should we use on a return system with 005 pump ? B5 or 3.0 lt B6 like Dan's? Now i use one from A4 B5 could that be a bottle neck?

MmmBoost

07-04-2011, 07:25 AM

I read over your other Thread. I see you ended up going return. But did you ever try difrent size holes on the filter with the returnless? when you used the 3/16 bit how did it work out? would you lose presure at high rpms?

I tried a 5/32" bit after on my first filter and it seemed that fuel pressure was more stable at idle, but it was still higher than 58 PSI. I would recommend the 3/16" hole and call it a day.

I didn't ever set up a gauge to test fuel pressure while driving so I can't tell you if pressure was dropping.

what filter should we use on a return system with 005 pump ? B5 or 3.0 lt B6 like Dan's? Now i use one from A4 B5 could that be a bottle neck?

I'm using a TT225 fuel filter and it's working just fine. I doubt a straight in/out filter would be a restriction.

Dan[FN]6262

07-04-2011, 07:55 AM

Honestly, they all probably use the same straight though filter lol

M-Hood

07-04-2011, 08:58 AM

what filter should we use on a return system with 005 pump ? B5 or 3.0 lt B6 like Dan's? Now i use one from A4 B5 could that be a bottle neck?

B5 A4 filter wont be a bottle neck since it can handle plenty of flow and even has threaded ends to use pretty large lines. I run 2 of the B5 filters on my car, 1 after my intank 044 pump and another one after my dual 044 pumps which is on a -8 line. If that 2nd filter was a restriction there would be no way I could flow enough fuel to hold a 55psi base fuel pressure or flow enough fuel to make 600+whp.

So you dont have to worry about having that B5 filter on your car.

mariosa4

07-04-2011, 01:30 PM

thanks everybody for quick answers.
Another quick question and sorry for hijack...do you face any problem with idle and big injectors with (siemens 875cc in my case) ? Is it possible to have smooth idle lets say on 1000cc injectors and 55 psi fuel pressure without raising the rpms? i can't fix it in my case and i have 30psi base fuel pressure. My tuner can't fix the idle fuel trims without raising the base idle rpms...

M-Hood

07-04-2011, 03:16 PM

Dan[FN]6262

07-04-2011, 03:47 PM

my idle is great with my Siemens 875cc injectors.

mariosa4

07-05-2011, 12:26 PM

5857;6658277']my idle is great with my Siemens 875cc injectors.

in that case then the problem must be my tune. Are you using Maestro Dan and what is your idle rpms?

dougyfresh

07-05-2011, 02:22 PM

mariosa4

07-06-2011, 03:09 AM

Yes. It is possible.

Your tuner needs to go back and give it another valiant effort.

My seimens 875s idle like stock at the stock idle speed and factory fuel pressure.

that's the problem we have here in Greece with the tuners Doug...

MmmBoost

07-06-2011, 08:41 AM

that's the problem we have here in Greece with the tuners Doug...

Email Fotis @ http://www.revlimit.gr/

He knows what's up when it comes to Motronic

Dan[FN]6262

07-06-2011, 08:54 AM

in that case then the problem must be my tune. Are you using Maestro Dan and what is your idle rpms?

Yes, I am using Maestro, and it stays around 800 rpms

mariosa4

07-06-2011, 11:44 AM

Email Fotis @ http://www.revlimit.gr/

He knows what's up when it comes to Motronic
thanks man , where did you find him[up]

5857;6662618']Yes, I am using Maestro, and it stays around 800 rpms
it's the coolest tuning suit but here in Greece we must play by the rules of the local market

MmmBoost

07-06-2011, 12:08 PM

thanks man , where did you find him[up]

Fotis is a great guy on all of the chip tuning forums. He is incredibly knowledgeable and extremely helpful. His little finger knows more about ME7+ than most of use would ever know combined. You won't regret it if you let him tune your car.

mariosa4

07-07-2011, 06:23 AM

thanks man i'll check him

Hansi

08-25-2011, 01:48 AM

How did you drill this bigger hole? Just drilled from outside the fuel filter? What about the plastic leftovers from the process, will that remain inside the fuel filter?

Dolphin18T

08-25-2011, 07:13 AM

How did you drill this bigger hole? Just drilled from outside the fuel filter? What about the plastic leftovers from the process, will that remain inside the fuel filter?

He flushed the plastic bit out with fuel but I'm curious as to how he drilled without damaging anything as well.

MmmBoost

08-25-2011, 07:17 AM

A drill bits flutes are designed to bring the chips to the top of the bit while drilling. Drill for a bit......stop.....bring the bit up and clean it....repeat.

There is nothing there to damage. It's just a piece of plastic with a section that narrows to a tiny hole. Drill....and stop worrying so much. lol.

the drill bit is like 3" long......it's not like you have to worry about it drilling into the regulator or anything. The drill bit just barely gets to the end of the orifice.

MmmBoost

08-25-2011, 07:20 AM

Dan[FN]6262

08-25-2011, 07:22 AM

with hands like a surgeon

613B6

08-25-2011, 07:30 AM

lol

Dolphin18T

08-25-2011, 11:03 AM

Ah... I thought the entire tube had to be drilled out, not just a small section. Thanks.

davkav

08-27-2011, 01:43 PM

Chris did your AFR normalize straight away or did it take a couple of minutes/drives/starts for it to adapt?

MmmBoost

08-28-2011, 09:43 AM

I don't understand the question. Could you clarify a bit more?

davkav

08-28-2011, 12:08 PM

Sorry what I meant was, when you drilled the orifice in the filter and then refit it, did your lambda reading at idle correct to stoich straight away?

MmmBoost

08-28-2011, 12:16 PM

My lambda was never off because of this fuel pressure issue because I was able to change some stuff in my tune to compensate.

You should see things go back to normal once fuel pressure returns to normal

CaRtharsis

11-04-2011, 06:57 AM

Add me to the list of having to drill the filter.

Wet0willy01

07-31-2012, 08:16 PM

Aeromotive 340 Stealth pump- Stock filter drilled @ 3/16"

http://youtu.be/XvhIKlbY5WE

http://youtu.be/88ZbHnoL1PA

vinny.dtw

08-13-2012, 08:19 AM

Bringing this back from the dead, as I finally installed my fuel pressure gauge and have the same issue. The question is for the people that did drill the filter, did they make sure there was enough fuel pressure at full throttle/load? Don't want to go drilling only to realize the fuel pressure drops when driving the car...

Wet0willy01

08-13-2012, 08:27 AM

The FPR will control the pressure. No worries on drilling causing negative effects. The issue with the stock is it's too restrictive. At rpm the FPR will be returning less fuel as the injectors will be consuming more fuel, returning less.

dougyfresh

08-13-2012, 08:58 AM

You need to stop modding your B6, Vince, and just drive it as-is.

onceover

04-03-2014, 06:00 PM

Bumping this from the dead.

Just picked up a new filter (PN 8E0 201 511 J) and I'm looking into the return line and cant seem to see the tube at all. Should this be visible or do I just start poking around in there with a drill?

edit: disregard that. Used a brighter light and its there.

incubusfc

12-04-2014, 07:57 PM

One that came with my 040 pump on left. The one I bought to better match the fuel line on the right.
http://farm6.static.flickr.com/5255/5552090772_0776267b65.jpg

http://farm6.static.flickr.com/5141/5552091110_8d77524ae8.jpg

http://farm6.static.flickr.com/5134/5551504403_5ecdfe3eb6.jpg

its the little things that make it or break it...

Sorry to bump an old thread, but I'm having fuel issues and ran into this thread.

It's not exactly the same, but here's the down low -
I can't really run up past 4k or run much boost in my GTRS, uni 630cc, Bosch 040 pump.
The car ends up leaning out. BAD. like 17:1. Now, I'm not 100% sure on my wideband calibration. It may be off slightly. But it's not significant.
I have been having problems with the fuel line going from the pump to the white access hatch in the tank. I got rid of the stock one because I felt like it was slightly kinking. So I put in a rubber fuel line. Long story short, I found out the hard way that fuel line, high pressure fuel line, and submersible fuel line are not one and the same.

I see that you have a much larger banjo fitting here; I think this would help me out because I feel like the 5/16th" hose is kinking and preventing fuel from flowing as much as it should. (It didn't always do this either) How did you hook this up to the 5/16 nipple on the inside of the white access hatch? And what kind of line/tubing did you use?

Sorry this post is kinda scatter brained.

Vino87

04-26-2018, 07:31 PM

I'm purposely bumping this thread from the dead for other people. This needs to be a sticky thread. This just saved my life. I've been experiencing a lean condition so I ended up buying a 034 motorsport 040 bosch fuel pump and I started to experience these issues. So will be drilling a new fuel filter with a 3/16 bit to solve my issues. THANK YOU SO MUCH FOR THIS THREAD!

fshademan

05-29-2019, 01:22 PM

That is the exploded view of the filter.
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new%20filter-12.jpg

The orifice is roughly around where the ALT is in my last name.
http://chrispaltzat.com/images/avant/build/FPR_testing/FPR_testing-new%20filter-13.jpg

Hey guys , I was reading through this thread and seems to me it may be the issue I’m having . I installed a Bosch 040 fuel pump and was getting no fuel at the rails . I swapped out the fuel filter , now there’s fuel at the rail although the fuel pressure gauge is showing no pressure .

I want to try drilling out the plastic piece like you did but my concern is how do you put it all back together ? Are you welding it back or drilling it while it’s assembled? If so doesn’t the remains from the plastic make it bad for the filter if it is slept inside??

If anyone could help me out it would be great. I’ve been stuck with this issue for 3 weeks now and it’s the last thing left before taking her to the tune

Thanks guys

fshademan

05-29-2019, 01:33 PM

Never mind just read the previous posts with the answers I need lol

J_L

02-24-2020, 01:05 PM

So, In my hunt for random missfires, I have some info that could be of help to others, regarding high fuel pressure.

my fuel setup is:
-B5 style return fuel setup
-Oem tt225 fuel filter to 6AN fuel line all the way to fuel rail.
-IE fuel rail+IE FPR adapter with Bosch 4bar FPR/Bosch 1000cc injectors
-Stock fuel feed line used as return line and connected to stock return line behind my TT225 filter.
-In tank DW300c 340lph fuel pump

I put a gauge on my fuel feed and it was 75 psi at idle, should be 58 minus vacum, about 52 psi.
Next, I ran a 6an line from the FPR and stright into the tank via the filler. Started the car and voila, 52 psi with vacum connected/58psi with vacum off.

Put it all back to the 75psi setup, and moved the gauge to the return line( my old feed line now used as return)
At idle, the return line had 42 psi of pressure.

I gonna try and run a new 6AN return back to the stock return behind my filter and try that. If not sufficient, I will run it all the way back to the top of the fuel tank.

M-Hood

03-02-2020, 01:10 PM

J_L

03-04-2020, 11:14 AM

What is the size of the stock B6 feed line compared to the stock B5 return line? Because I still run a stock B5 return line with dual Bosch 044 pumps and still hold a 52-55 psi base fuel pressure. My stock return line is connected to a surge tank and then from the surge tank to the OEM tank.

I belive the stock feed is about 5/16 Mike, or about 8mm ID.
Update: Put in a new 6AN return line back to stock return line next to the filter + drilled out the return elbow on the fuel tank lid on driver side, still running high rail pressure, 65 psi with vacum line atached to 4bar Bosch FPR.
Purchased a new Aeroflow 1200hp rated adjustable FPR and ditched the stock Bosch unit and adjusted base pressure to 58psi/47 psi with vacum.
All is now good, glad I didnt have to mess with the B6 Bermuda style fuel return system inside the tank.

Next up tonight, instaling LUK B7 RS4 clutch and TTV racing steel SMFW + filling up the gearbox and diff with Ravenol 75w-80/75w-90 oil[wrench]
The stock clutch never had a chance once the 5858 hit 18 psi.
165360

BumblebVR6

12-16-2021, 09:59 AM

I belive the stock feed is about 5/16 Mike, or about 8mm ID.
Update: Put in a new 6AN return line back to stock return line next to the filter + drilled out the return elbow on the fuel tank lid on driver side, still running high rail pressure, 65 psi with vacum line atached to 4bar Bosch FPR.
Purchased a new Aeroflow 1200hp rated adjustable FPR and ditched the stock Bosch unit and adjusted base pressure to 58psi/47 psi with vacum.
All is now good, glad I didnt have to mess with the B6 Bermuda style fuel return system inside the tank.

Next up tonight, instaling LUK B7 RS4 clutch and TTV racing steel SMFW + filling up the gearbox and diff with Ravenol 75w-80/75w-90 oil[wrench]
The stock clutch never had a chance once the 5858 hit 18 psi.
165360

Did you mount the regulator directly to the fuel rail?

EuroxS4

12-16-2021, 01:15 PM

Holy Necro bump lol.

crisbm

09-24-2023, 03:01 AM

Hi guys, I have exactly the same problem but on a4 b5 1.8t, changed 2 fprs from Bosch 4 bar, but the pressure I get when I hook up the gauge to the return line moves between 6 and 7 bar like crazy, fuel consumption its a bit higher and doesnt make the requested boost in gears 4 and 5, in the lower gears boost its fine, any ideas how to reduce the fuel pressure? I put down here 3 runs, 2nd gear pull, 3rd gear pull and 4th gear pull:

https://youtube.com/shorts/z648rYTUlbc?si=SjtN4cm8ekOUdTho

https://youtube.com/shorts/QtY0gjYzAv4?si=4A9-UjXrDeUVMYBK

https://youtube.com/shorts/ecdEJy1FCLo?si=Z9aIFeIsvAqJNgXR