First time poster to this excellent site. Lots of good info. Entered the Jeep world a couple months ago by aquiring a '99 XJ with a blown 4.0 motor. Replaced it with a salvage unit, ran great. Jumped in it a couple days ago and no start. Checked all fuses, all good. Finally pushed the throttle pedal down a bit and it fired right up and runs like it should. Dies as soon as you let off though. I'm thinking TPS, any other thoughts? I searched pretty far back on here, but couldn't quite find the answer. Thanks

 

Sounds like the IAC on that one. I had the same problem a couple of months ago.

 

A new IAC did the trick. Thanks for the recomendation.