Yellowgreenwood

LeesVet- I'm pretty sure that you have located my problem! Restarted car (barely started), got it to finally idle, got out unplugged individual injectors to see if there was much difference, none to speak of. Wiggled entire harness on driver's side, nothing. Moved to passenger side, unplugged individual injectors, still no REAL change. Pushed on wiring going down to "block". Ran great. released pressure, misfire again, pushed on wiring, ran better (plugs may be fouled). Going to let car cool off and recheck.

leesvet

I chased a mystery misfire for MONTHS. I did everything in the book and then stuff that was pure guessing. Nothing worked or helped.
The symptoms were easy, constant misfire, rich, fouled plugs (that moved from one cyl to another) and the more throttle it got the worse it ran.

Finally I moved the harness around and found the problem. Like I stated previously, I had to chop out the entire driver side harness to the sensors and injector and solder in all new wire. \

If you look closely at yours you will see some damaged wire strands and that tells you there is shorting or cross-signaling in the circuits. Your description of temp and other sensors is what told ME what your problem is.

The wire on the C4 engine harness is crap. Expect problems as it ages or high miles.

Good luck, I hope this has helped.

Yellowgreenwood

As it turned out, it was the ECM. will give details on repair later.