I know there are a lot of posts with misfirings but there are no solutions. I have an APR Stage 2 setup and under boost between 2500 and 3500 rpms, the car shudders with misfirings. I have replaced coilpacks, controller module,plugs and so on. I replaced the DV with a forge. I even did a timing belt kit as I am at 80k. I watch the boost gradually gain with even throttle but when I romp on it, it misfires. It only seems to happen when the engine is warm. Am I missing a leak somewhere? I used the VAG to watch my cylinders misfire and that is what prompted me to change out the coil packs and module. If I force the the misfires, I get a CEL. Codes are for misfires. Duh, I already know that. Please help![:@]

97 A4 1.8T FWD
APR Stage 2
APR cat back
APR boost gauge
EVO CAI
Short shifter

 

Just to close the loop. I replaced the Bosch Platinum 4's with NGK BKR7E gapped to .028

It runs like a raped ape now with no misfiring.

 

did you try to replace the plugs, now that you got more boost you need better spark. also bbigg dont you mean raped date.

 

Damn thats tuff.... If you replaced plugs, coil packs and ICM then the only things i can think of are badcoil pack wiring harness/wires or a leaking head gasket or other things that can cause a rich condition like the MAF or possibly pre cat 02 sensor. Im sure that you would be getting other codes along with the misfire codes if it were something not directlyignition related. You sure you replaced the plugs?? I had very similar symptoms when i had 2 cracked plugs... What kind of plugs are you using at what gap??? With stage 2 you are running higher boost, etc. and should be using a heat range cooler than stock (NGK BKR7E for example) gapped pretty tight at .028


Edit- Woops didnt see you are running fine now.. Cool...

 

Here is the latest. I did notice when I replaced the old Bosch Platinum 4's. There were two plugs with hairline cracks in the ceramic insulators. The new NGK BRK7E's run much better but I can still feel a little hesitance in the top end of the boost. None of the old plugs were running rich or lean. I read on another post that maybe the injector could have a leak. Not sure if that could be as changing plugs and gapping them properly fixed 90% of the problem. So is it electrical (ignition)or air (vacuum/ boost leak) related. I even replaced the spark plug connector tubes. Any more thoughts.

 

Have you heard of putting dielectric grease at the bottom of the spark plug tube to keep the plug from arcing to the head?