S6 running problems, continued ad nauseum

[Larry C Leung]

BOY, do I know how you feel (stumbling 200Q, just swapped ECU's to swe if
the chipped one is screwed up, no codes on the known good one either
(except overboost, which was expected due to the Charlie Spring).

LL - NY

On Sat, 15 Dec 2001 17:37:14 -0600 Steve Marinello
<smarinello at telocity.com> writes:
>Having obtained an ignition control unit/power output stage device for
>my S6
>avant ( at a most reasonable price with the assistance of a list
>member), I
>had hopes that the intermittent missing problem I had would finally be
>put
>to rest.  Unfortunately, I have to report that there was no change.
>
>The car came to me from KAR with Hoppen/MTM software mods, RS2
>exhaust
>manifold and RS2 injectors.  The car exhibited widely intermittent
>episodes
>of running on four cylinders, with the culprit always being #4.  An
>Audi
>dealer tech, the only one I let work on the urq, checked the system
>and was
>almost sure it was a bad injector, as everything else checked out.
>The coil
>packs had been replaced less than 20k earlier and the dealer records
>seem to
>point to this problem existing way back and never being fully
>resolved,
>although it would go away for long periods.
>
>Everything appeared to be firing correctly when the miss occurred and
>disconnecting the injector lead had no effect.  Coil packs were
>swapped to
>no avail.  The injectors were replaced with stock units, as the car
>appeared
>to be running rich most of the time.  That was a positive step, but
>unfortunately it did not cure the intermittent missing.  New plugs and
>new
>connectors were also installed, again, without resolving the problem.
>Grounds were cleaned and reattached.  The Motronic box was pulled to
>make
>sure all the connectors looked clean and that nothing was apparent
>down
>there.  I really had hopes for the stage device.
>
>All I can come up with now is a problem injector lead to #4 (but it
>was
>firing when the miss occurred and it was disconnected from the
>injector) or
>a broken valve spring hanging up periodically.  It stinks to h*ll when
>it
>misses, so there's plenty of gas there to overload the cats.  The fact
>that
>it is always at #4 sort of precludes the MAF or other general system
>problem, doesn't it?
>
>The car also bucks/misses badly in 1st and 2nd when it seems to be in
>the
>mood to shut down #4 completely.  An intermittent miss is apparent in
>the
>idle.  Sometimes, you can trigger the full five minus one equals four
>cylinder running by getting into the gas and accelerating in 2nd, 3rd
>or
>4th.
>
>I'm approaching a sense of despondency over what should be a very
>enjoyable
>car.  Is this what I get for having a dependable urq?
>
>I'm on my knees...no, actually flat on my back...can the brain trust
>of
>these lists please provide further assistance?!
>
>TIA,
>
>Steve
>