[s-cars] Non S-Car: A4 Stumble

[Brian Powell]

Greetings listers,

My wife's A4 (96 12v V6) is having a stumble under load problem that I
cannot trace down. I have tried Audiworld, etc. so I will try here.

Car seems fine, idles fine, etc. Sometimes under load (accelerating
from 2k rpm in 3rd gear) the car begins to stumble badly. It feels
like a pre-detonation and drop back in timing; however, the gas is
what she has always used without problem. I hooked up VAG-COM and
sometimes an error code is logged:

16689 - cylinder 5 misfire detected 
p0305 - 69-00 - cylinder 2

(I'm not sure what that cylinder 2 part of the above message means).

This code does not always appear after a stumble incident (if I clear
the code, go drive and get it stumble); however, it always comes
eventually. I have moved the plugs around, tested the coils, plug
wires, PSO, etc. and nothing has had an impact. This car has three
coils and one PSO so, if the coil were the issue, I should register
misfires on cylinder 3 also (since 5 and 3 are on the same coil).

It doesn't ever turn on the CEL, but, sometimes does enter the above
error code. The misfire detection (as I understand it) will flip the
code if there are any slight deviations so it is only an indicator, I
suppose.

I have thought about poor fuel delivery, FPR, etc.; however, any of
those issues should register misfires on other cylinders, not just 5.

Anyone have any tips or suggestions? 

-- 
Cheers,
Brian