My brother is nearing the completion of his 5.3 swap into a 87 Jeep Grand Wagoneer. I'm helping him with the final steps, and need to know a little bit about what I need to expect to do to tune this thing. I have already removed VATS, but the engine still doesn't want to fire.

Is there anything else that I need to do to the computer or do I need to start chasing down other electrical gremlins?

 

VATS is all to make it run. Do you have spark, fuel pressure, injector pulse? Make sure the pink wires have power while cranking aswell as with key in on position. The PCM must have the constant power if you were able to reflash it.

 

I've got fuel pressure and spark. Got late and didn't check injector pulse... I was just looking back over the logs and noticed that it never picked up any TPS... I wouldn't think that would keep it from running (It's got a tps sensor low voltage code... I assume that means I need a new one)

 

Unplug the TPS and try it. If the TPS is showing WOT then it will shut the fuel off.

 

Nope. It's showing 0. That was my first thing to try when I saw a tps error because I knew that it would not run if floored.

 

Is it getting a crank signal?