I recently purchased an 88 cherokee (4.0 4wd) engine runs and drives for about 1 mile or so. Then stalls out, then wont start for 10-15min then it'll start again but run for a shorter amount of time, until it has rested for an extended amount of time. I am new to jeeps, and the 4.0. I have started working on cruiser54's list, but where might be the best place to start to fix this issue?

 

Does it have spark while it won't restart?

 

yes there is spark, it'll start but, backfires and dies. After doing some reading I'm going to check the MAP and vacuum lines

 

Definately go over 54's list first, and clean all electrical connections. Otherwise, according to your description, it sounds as though it runs fine when dead cold, but not when it's up to operating temperature. A cold engine needs less air and more fuel (rich mixture) than a hot engine. If you had a vacuum leak you'd have more air and less fuel (lean mixture), so I find it unlikely a vacuum leak is the cause of the problem. I would clean the Idle Air Control (IAC), and perhaps replace the engine temp sending unit, the one that sends a signal to the ECU, though you may want to check connections and condition of wiring first. If yours is the same as my '89 4.0, it's conveniently (not!) located toward the front of the engine underneath the exaust manifold.

I'm sure more qualified advisors than I will chime in here, but go over 54's recommendations before you do anything else.

Good luck!

 

Listen to The Hammer. LOL.

Tips 1 through 5 at www.cruiser54.com.

 

Cruiser's tips are a must-do. Also clean the connections to that ceramic fuel pump resistor or delete it.

 

Sorry wrong thread.