Big Daddy J...you got the doctor on your case now...along with a few others in here, if GS92 can't fix it, you're doing something wrong. First, you did mention that you took the cats off, right? I asked this in your exhaust thread...what happens to the thermactor pipe when you do that, and where it goes? I wish I could help more, but I thought of that with one of your first posts. When my '88 had started doing the same things, I hadn't been here yet, so I ran the gambit with repairs and parts.

The eventual combo was this...

The ECM wire like you mentioned.
IAC
TPS
ICM
Cap and Rotor
Plugs
Wires
Wire looms for #7 & 8 wires
O2 Sensor
And yes, eventually (it was just time...not because of this stuff) a new engine.

It eventually got the job done, unforetunately, I don't know which one did it.

 

ah...got my threads confused. Thought you were the one posting about the exhaust in the cab.