Cylinder 3 misfire

**himynameissteve** · 11-03-2008 07:05 PM

i have a cylinder 3 mis-fire on my 97 audi a4 1.8t im not sure whether or not its the coil packs or the mas airflow sensor..i changed the spark plugs and nothing changed the car is still sputtering and the check engine light is still on...any input or suggestions?

**firstars** · 11-03-2008 07:18 PM

99.9 % sure its ICM or Coil packs... a

**djwimbo** · 11-03-2008 07:29 PM

what he said. Swap the coil pack from #3 onto #1 and see if the misfire moves to cylinder #1. The likelihood of it being a faulty injector are slim, and the MAF shouldn't cause a misfire on only 1 cylinder.

If I were to diagnose it in person the first thing I would test would be the coil.

**Seerlah** · 11-03-2008 07:30 PM

Swap ignition coils from cylinder 2 and 3. If the misfire moves to cylinder 2, then replace that coil.

Edit: djwimbo beat me to it.

**firstars** · 11-03-2008 07:35 PM

i should mention I now have a new misfire on cylinder 3. Just replaced both ICM and coil on cyl 3! so i am the .01% i mentioned. But I have replaced like 10 coils and 3 ICM's since owning B5 A4's.

**djwimbo** · 11-03-2008 08:21 PM

Originally Posted by firstarsbrnwhit

i should mention I now have a new misfire on cylinder 3. Just replaced both ICM and coil on cyl 3! so i am the .01% i mentioned. But I have replaced like 10 coils and 3 ICM's since owning B5 A4's.

well, time to start checking the other things.
Compression check would be a good thing to get out of the way, not that I would think that's the issue, you just want to eliminate it.
Second, make sure the injector is firing.

There is always the possibility that there's a wiring issue between the ICM and the coil itself (seen that happen too). Otherwise pull the plug out, put it in the coil and plug the coil in. If you lay the plug on the valve cover you should be able to see if it's arcing. I've seen a lot of people crack the porcelain on new plug installs and end up with the same problem they started with.

**firstars** · 11-03-2008 08:34 PM

I wasn't clear about my situation. I had severe multiple misfires which I fixed by changing the ICM. A few months later I had cyl. 3 misfire and changed the coil which fixed the problem. Now I'm having another misfire. Just wanted to clarify this was three different accounts, not failed solutions to one. Don't wanna thread jack (although im sure coil or icm and this guy will be golden) just scanned it tonight and haven't sorted it out. Thanks for the tips though.

**himynameissteve** · 11-04-2008 08:22 AM

thanks for the help im going to trying switching my coils and eliminate that problem today and ill also run a quick compression check aswell. thanks for the help.