Bad Computer Symptoms - For Diagnosis

So, I thought I'd just post up on what the symptoms were with my XJ which led me to diagnosing that it was the computer that was bad. In case anybody else has similar symptoms, hopefully this will save some leg work, time, and money with throwing parts at it.

1. Fuel pump would not prime when the key was turned to on. It would either not prime at all or take a few seconds before it would.
2. Jeep would start up (when the fuel pump would prime), but would stall after 1-2 minutes every time.
3. After stalling, the fuel pump would cycle on/off randomly, along with the electrical fan and vacuum servo.
4. Check Engine Light was on and throwing P0705 and P1694 codes.
5. The position of the computer and/or tapping it would cause the fuel pump to react differently.

Well, I hope that helps someone. I know it was driving me crazy for a bit.

Thanks for this. It's not everyday that people postup when they find solutions to things.

So how's the replacement doing?

Yeah, Seth, you were right, screw the part numbers. It works fine! Never listen to the damn dealer!

:thumbup: good deal

Hm, it sounded to me more like a bad connection or a grounding issue than a bad computer per se... Did you try hooking the old one back up?

dupe post

no, it was definitely the computer. The old one still does the same thing.