My 91 n/a AT takes a little longer than normal to start, but runs like normal when cold. Then when it warms up it just runs like the AFM is unplugged. Just kinda limps...but I have swapped out 3 AFMs, the OMP, the ECU, the UIM and LIM, the oil injectors, and finally secondary injectors. I wasn't getting any codes for some reason.
Again, the car drives fine for the first minute or two, but once it warms up, it quickly runs like crap and doesn't want to accelerate. After completely warmed up, I can slowly accelerate, but if I step on the gas, it will shut off.
I'm out of ideas...oh yeah, the compression is good.

 

Water thermo sensor, or connector...Try that...

 

I checked it...still plugged up-worked before I pulled the motor. Could the thermowax make it run like sh*t when warm?

 

ttt

 

If the thermowax was bad, you would either have no fast idle on startup, or a fast idle all the time, depending on which way it "broke". Shouldn't do what you're describing, either way...

You check the water thermo sensor output at the ECU? The reason I'm pressing this sensor is because what you describe (takes longer to start, etc...) are classic symptoms of a bad thermo sensor circuit. Been there...

Even if it's not that sensor, you still need to get down to the ECU and start checking things out, or you'll just be throwing parts at it. We have a very informative thread going right now on just how to do this-

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/troubleshooting-your-car-ecu-340578/

 

Why are you swapping parts out of it's not triggering codes???



-Ted