[acna_pcc] Still on 4 cylinders.....No Dice!

[AUDIJIM at aol.com]

Harold,

Thank you very much for your comments. But with your comments comes a few 
more questions. First, this is a 1993 Audi S4 with AAN 20 valve turbo engine. Why 
would the Throttle position potentiometer (G69)/Closed throttle position 
switch (F60) have anything to do with #4 cylinder? The AAN does not have any 
throttle adaptation other than the correct position of G69/F60. When I start the 
engine, I can pull the #4 connector from the injector, and NOT get any change in 
rough idle. If I pull any one of the other 4 cylinders, I get a change in 
rough running due to the engine now trying to run on 3 cylinders. I pull the #4 
injector connector only to prove that there is not any change in running 
condition. I have tested and changed nearly everything for the ignition and fuel 
injection systems. I thought I had this licked with the lifter change. They can 
be intermittent due to being under or over pumped. I have also changed the 
throttle and G69/F60 from a known good working engine (my spare AAN) That didn't 
help anything. I disagree with you about an intermittent piston ring or valve 
problem. I might have a hair line crack in a ring that gets better with 
heat/time. If I blip the throttle, it might open up and create a lower compression 
and then seal up again, that just a guess of course. Without pulling the 
cylinder head, I will not know what is going on with the valves or the pistons.

Thanks again,

Jim