Car stuttering when accelerating

[Xplycko]

I have a 2000 C5 2.7 6 speed. I was heading home the other night from work and it just started stuttering bad when on the fuel. It idles fine and revs decent when in neutral. It happens when I give it throttle under load mostly, the more throttle I give the worse it gets, it almost bucks but not quite. It has new icm's new plugs, have a new maf coming cause this one is bad. It honestly feels like a fuel issue to me. Would the fuel pressure reg do this?

Sent from my LGL62VL using Audizine mobile app

[cu52]

Any codes?

Sent from my VS988 using Tapatalk

[Xplycko]

Maf code and rear o2 but the pigs are causing that and the maf will be here monday. I will get codes again monday after I put the new maf in. I dont have a scanner

Sent from my LGL62VL using Audizine mobile app

[rguil]

You check your throttle body boot? Might be torn and leaking air espically if its stock, i hate those things

[Xplycko]

Just installed s brand new samco a week a go. I have also done a leak down test, dont have a smoker. Thanks for the ideas guys, thats what im trying to do is narrow it down. Its more than 1 cylinder acting up. Could be a couple coils but i have never had more then 1 fail at a time. Do the fuel pumps in these cars get weak before failure or fail all at once like most do?

Sent from my LGL62VL using Audizine mobile app

[rguil]

I doubt its your fuel pump, its more of an all or nothing kind of thing. Fuel pressure regulator, again i doubt it.
Nevertheless, a good idea would be to change your fuel filter. You should of seen the one that came out of my 210k car.

I really recommend you get VCDS lite (or pirate the full version) with a Ebay cable so you can properly diagnose your car. It is almost a requirement to have in your a6 at all times!
Lets see if the new maf fixes it, it is very imporant in these cars for them to run properly, especially under boost/load. Your crap maf might be reading all sorts of messed up crap higher up in the rpm range

I look forward to results,

[Xplycko]

Thx, i appreciate the advice. Can you recommend the ebay cable i need and where to dl the free version? I dont like pirating.

Sent from my LGL62VL using Audizine mobile app

[rguil]

http://www.ross-tech.com/vcds/download/index.php

http://www.ebay.com/itm/VAG-COM-VCDS...oAAOSw1vlUyU7M

[Xplycko]

Wow that was fast. Thx rguil!

Sent from my LGL62VL using Audizine mobile app

[Xplycko]

So lite 1.2 is the one I want? Can I have someone tune from this remotely or do I need to full version for tuning? Thx

Sent from my LGL62VL using Audizine mobile app

[Corradovolksb]

Yah the lite version will allow you to do most of the stuff that vcds full version will. That vagcom cable will allow you to flash with nefmoto flasher and log with me7logger. Pm me and we'll talk.

[cu52]

here is a genuine cable for sale in our classifieds. Same one I have. Works for B5 and C5 as well as older.

http://www.audizine.com/forum/showth...ighlight=cable

]

[AudiTuner1187]

I experienced same exact thing, did 20 boost leak tests, sent out injectors, changed fuel pump/filter, FPR, plugs, Eva, leak down/compression and all lead nowhere till I changed all my coils out and boom, fixed. I was getting random multiple misfire (would take a long time to come back once cleared) and 02s were reading lean. Come to find out, raw fuel will fool an 02 into a lean reading. Maybe you won't chase for as long as I did 😁. Once I hit about 6-7 psi, misfires like crazy and no power. GL

Sent from my SM-G950U using Audizine mobile app

[harryn]

When was the last time you checked your chain tensioner pads? Just throwing it out there, since that was my case as well. I'm still new to Audi (mainly a BMW guy), but figured I share this question as it was the cure for my misfire and no power issue.

[Xplycko]

Well I had the same issue AT1187 had. I have never seen this before but I had 2 coils go bad at the same time. I had checked everything but the coils because they were new. But changed out the 2 coils and bam were back in business. I went ahead and put new icm's on and held onto the old one's. Idk for sure but maybe those icm's were being hard on coils idk. I also boost tested it and no leaks anywhere. New maf in to and man she runs like a top! All I need to do now is finish the exhaust, install a boost gauge and throw in my forge splitters and it's off to stage 2 town!

[rguil]

Well I had the same issue AT1187 had. I have never seen this before but I had 2 coils go bad at the same time. I had checked everything but the coils because they were new. But changed out the 2 coils and bam were back in business. I went ahead and put new icm's on and held onto the old one's. Idk for sure but maybe those icm's were being hard on coils idk. I also boost tested it and no leaks anywhere. New maf in to and man she runs like a top! All I need to do now is finish the exhaust, install a boost gauge and throw in my forge splitters and it's off to stage 2 town!

Good!

[rat9]

I have a 2001 B5 S4 with maybe the same issue. Idles perfectly and runs fine when I baby it, NO CODES. Replaced the MAF and the plugs. No air leaks. When I hit the gas in higher gears at low RPM I have stuttering and almost no torque. I am AMAZED that it doesn't throw codes because it is pretty terrible feeling. I have a bluetooth code reader and the torque app on android, I watch graphs of boost and I dont see anything odd....

Only 130K on this S4! Still on my first turbos. Also I have the REVO firmware.

Maybe I should try coil packs? Any recommendations on brand that isn't from AUDI so this doesn't cost me a ton?

[rguil]

I have a 2001 B5 S4 with maybe the same issue. Idles perfectly and runs fine when I baby it, NO CODES. Replaced the MAF and the plugs. No air leaks. When I hit the gas in higher gears at low RPM I have stuttering and almost no torque. I am AMAZED that it doesn't throw codes because it is pretty terrible feeling. I have a bluetooth code reader and the torque app on android, I watch graphs of boost and I dont see anything odd....

Only 130K on this S4! Still on my first turbos. Also I have the REVO firmware.

Maybe I should try coil packs? Any recommendations on brand that isn't from AUDI so this doesn't cost me a ton?

Post logs before throwing money at it.
http://www.audizine.com/forum/showth...raph-Logs-****

[rat9]

--- update ---

Well I threw money at it because I had more of that than time and sense at the moment.

What didn't fix it:
*Fuel pressure regulator
*plugs
*intake manifold/boost pressure sensor
*MAF
*2x Ignition control modules

Things that were replaced at once that solved it:
*coilpacks (BERU)
*turbo diverter valves (Swedish $25)
*water temp sensor (Ebay)

So one or more of these three was the issue. WOW it feels good to have smooth mid and high end torque again. Even though all the plastic bits are cracking and falling off, the S4 just keeps on going!

[afreeman1984]

I bet it was your coilpacks they go bad all the time.

--- update ---

Well I threw money at it because I had more of that than time and sense at the moment.

What didn't fix it:
*Fuel pressure regulator
*plugs
*intake manifold/boost pressure sensor
*MAF
*2x Ignition control modules

Things that were replaced at once that solved it:
*coilpacks (BERU)
*turbo diverter valves (Swedish $25)
*water temp sensor (Ebay)

So one or more of these three was the issue. WOW it feels good to have smooth mid and high end torque again. Even though all the plastic bits are cracking and falling off, the S4 just keeps on going!