[V8] Three codes

[Coleman, David]

Hello All,

Before I go mad w/ various part swaps, I wonder if anyone has any
advice:

My '91 5-speed has an AudiConnection 4.2 installed with the original
unmodified 3.6 ECU -- a combination known to work with no problems
whatsoever.  But since the install I've had a couple symptoms that occur
sporadically, typically a rough stumbling w/ general lack of power under
load at low rpms, and seems to clear up once past 3.5k or so.   Other
times it will barely run, engine idle fluctuating violently, and when
trying to get underway, protests by bucking and snorting, making any
forward progress nigh impossible.

In both/all cases, the engine seems to run quite rich.  Stinks to high
heaven, and the tailpipe is very sooty black.  When it's in full protest
mode, I smell raw gas while cranking, which will flood the sucker out.
Here's how things have gone down, code-pulling-wise, over the past 50
miles:

1)  Car runs pretty well, except under low rpm load where it sputters
and farts --  Code:  2111 (ECU) was only code.  Replaced plugs, FPR, air
cleaner, checked vent hoses.  Runs pert near flawless for 5-10 miles
until low-load symptoms creep back into picture.  Gradually gets worse
across wider RPM range until:

2)  Car in full protest mode, barely runs and is essentially undriveable
-- Code:  2413 ("Mixture problem, runs rich or lean, vacuum leak"). .
No crap.   Tap ISV w/ wrench, clean contacts on TPS, eyeball vent hoses
again.  Now no start, strong fuel odor points to obvious flooding.  Pull
back spark wires and starts up, same nasty running condition.  Pull code
again: 2413 is gone, replaced by 2213 (ISV).   Shut down, restart, try
to clear its throat a bit, code back to 2413.

I have a 3.6 TPS I can swap on, a spare ISV of unknown condition, and a
spare MAF sensor of unknown condition.   I can swap the parts to see
what happens, but wonder if I should be looking at new plug wires, caps,
etc.?   Did I miss a bad hose?  Any thoughts are welcome, otherwise I'll
post results from parts swapping.

DaveC.





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