Topic: P1391 and TJ runs fine

[Toonces]

Back in April my early 97 TJ 2.5 gave up the ghost (rather spectacularly) so I bought a reman long block from a company in Phoenix and had it installed by a local mechanic. Shortly after I got the jeep back I started getting a P1391. The jeep isn't missing and runs great. I replaced the Crankshaft Sensor with a new MOPAR brand and cleared the code. A day later and the fault is back. Since I had reused my previous distributor I replaced it with a Cardone reman and reset the code. a day later and the fault is back. I started inspecting my engine harness and found a lot of brittle wire and some hacked connectors so I got a replacement harness from a late 97 TJ and proceeded to swap the harness out. Along the way I replaced all the sensors that were different (manifold temp, water temp, TPS & MAP) from the early 97 to late 97 versions with MOPAR parts. The last thing on the list was to replace the ECU which I did yesterday with one for a late 97 flashed with the latest available software. Today, the code is back. I'm at my wits end trying to figure out what the cause can be. As far as I can tell, I have replaced everything that has to do with the fault and it's still coming back. Did I miss something to test? I'm not a mechanic but am comfortable with troubleshooting and working/learning how to fix things on my Jeep. I am about to take it into the shop but would really like to learn to fix it myself.

Thanks for any assistance!

Toonces

[sharpxmen]

not sure what that code is (and I'm too lazy to look) but I'm guessing it's related to the CPS based on what you say. Since you've done all that and given that you replaced the engine I would maybe look at the cam sensor and the position of the distributor, if it's slightly clocked it could cause an out of sync issue but since your ignition is off the crank sensor might still be running ok

that's all I have as you seem to have covered everything else.