probably a really dumb question, but has to do with changing the flywheel...
 

Okay, so I just dropped a new junkyard motor in my 1990 pioneer. I got the motor out of a 92-96 xj(cant remember the year). I stripped everything down and used all my old sensors and wiring harness. The only thing I didn't change was the flywheel. I made sure every ground everywhere is hooked up and has a good connection. I have no spark from the coil. People keep telling me it has to do with me not putting my flywheel on this new motor and its keeping the cps from working.

My question, and again may be a dumb one. Would splicing in a cps sensor to match that flywheel possibly work? Or does the computer regulate the output of power coming from the cps, not the sensor itself?

I can't remember is your 90 a Renix motor? If it is then you need to swap the flywheel out with the one off your 90 motor. If they are both the H.O motors then the CPS is the same.

yeah its a renix

It stinks but you have to either remove the motor or trans and put the correct flywheel in. The H.O flywheel won't work with the Renix truck.