I'm on teh original harness in an 85, so you can just assume that my wiring is generally garbage. I've spliced and repaired it pretty well in a couple of dedicated sessions, but there's always spots in harnesses you either don't see or don't get to.

My reason for looking at the AMM is:

1) Another guy with the same problem has replaced everything I haven't except the AMM and o2 sensor (ignition, coil, etc.) and is still having the problem.

2) I had a similar problem in the summer that was often solved by reseating the AMM connector (unplug replug).

The question is, if it is the AMM, whether its the harness/connector or AMM itself, and as far as I've found testing an AMM is like calling the minute of the day using the sun's position.

I'll check all the grounds next chance I get and trace the harness for bad spots. I'm a bit petrified of messing with teh ECU for fear of damaging it in any way (250k miles) and having to suck up the cost of the replacement, but I'll look into that one too.

Thanks,
Rick