Infrequent Engine Misfire

[Jkilla71]

I have a problem with my 1999 A4 Avant 1.8t.

I have an APR chip and K&N filter and upgraded DV valve.

I have been experiencing what I describe as a skip, miss or maybe a misfire when in manual mode on the Tiptronic and putting a heavy load on the engine.

It happens once or twice usually but I have counted up to three times under hard acceleration but very rare. The skips do not happen in successive revolutions but 1 or 2 seconds apart if it skips a second time at all.

Under normal driving conditions or in full automatic I don’t experience it at all.

I have read about bad coil packs on this site but it doesn’t seem likely to me as this has gone on for months now and has not degraded further or displayed a dash warning light, ever. I am sure I am getting full boost as the turbo gauge is consistently steady 14.5.

Any ideas would be much appreciated?


TY

Joel

[Jkilla71]

Is it possible that the stock injectors could be the problem?

[Mawhitey]

possibly, but more likely incorrectly gapped plugs, gap them to .28 for chipped and try that

[Jkilla71]

I changed the plugs but did not have a plug gaper at the time and soon as I hit the gas the engine light came on. I then pulled the plugs out and gaped them @ .28. I then put everything back together and took it for a ride. The skip was gone but the car still didn’t have all its power back.

I then went to Advanced Auto and had the code read: cylinder 2 & 3 had a misfire. I still was not convinced it was the coil packs due to many posts I have read about people replacing the coil packs and still having a misfire. I then bought some MAF cleaner and cleaned-up the MAF. I took the car for a drive and I was still not totally satisfied with the car but I remember thinking the performance felt better. I am not sure what the reason but the engine light had gone off by itself the next time I shut it down and restarted it but it still felt like it wasn’t 100%.


I then bought and installed the N75 “J” valve and 4 new coil packs and I think the car is faster than I can ever remember now.

Unfortunately I am not sure what was the deciding factor with fixing my car but I only spent a couple hundred dollars and it is running great now.

I also bought the “Panzer Skid Plate” from dieselgeek.com (awesome product) because I had a weak moment and had let Jiffy Lube change my oil. They couldn’t get my lower belly pan back on and my buddy witnessed the Tech rip it off the car and discard it. I told the manger and he yelled at the Tech but when I got it home the belly pan was dragging due to some screws missing and had a big rip. I blame myself for using them but the aluminum skid plate from diesel geek is well worth the $250 and it also amplifies the whistle from the turbo nicely.


TY

JG

I also added a 5 bar FPR that I forgot when I did the above changes

[bammercole]

Glad this is going, may have just been a coil pack failing under real heavy load, although like you i'm skeptical of all the times people say every problem is the coil packs.