I have a tpi harness off an 85, which I would rather not use because of the spliced wires it contains. I have been looking through wiring diagrams for a 92, and I've noticed that there aren't many differences between a tbi and tpi harness. I am going to keep looking through and make notes of all the differences I see. So far, this is what I've noticed. Please feel free to correct me or add anything I have missed.

I believe the tps and iac wiring would be too short on the tbi harness, so I would need to remove those, and replace them with the wires from the tpi. Would need to do the same with the injector wiring. I also know I would have to repin the connections at the ecm. Anything else I haven't noticed yet?

 

Yes, you will need to eliminate the ESC module (jump the wire from the knock sens. to the wire that goes to the computer),change the knock sens., and change the plug for the EGR. Under the dash you will have to eliminate the speed buffer (jump the two brown wires together), run the yellow and the purple down to the computer, and run the red wire on the speed buffer to the computer. In the 15 pin connector, you will need to eliminate the purple/white wire.(it's for crank fuel not used on TPI)