i have a 89 4.0 xj it has 214000 miles on it. I dont drive it very much (i have a company truck) about 4 or 5 months ago i put 33"12.50"s on it thats were i started having troubles with the jeep. I had to ajust the kick down on it but after a couple of weeks i noticed i had no power. i started with the fuel side of everything bucuase my friend that i got the jeep from had replaced the cap roter wires and plugs about 6 months before i got it. After replacing the fuel filter it started running a lot better but still seemed like it was low on power about 2 months ago i took the jeep back home and we took it out a couple days it would start to get hot and stall out. i realized that the cap on the over flow for the radiator was stripped and when it would build up pressure it was spraying every where in the engine bay. i fixed that and it helped out a lot. When i got back home i started having problems with it dying when i stopped. Then yesterday i got my truck stuck and had to use the jeep to pull it out. there was no real work done by the jeep just need the extra pull to help it on the slick wood. After we got the truck out the jeep died when we tryed to start it back up it it took about 10 seconds for it to start when i did is sounded like a old 3 cylender tractor running on 1 cylender it ran like that for about 30 seconds and then it died i went out there today and tryed to start it up and it would not start it tryed but sounded like is was missing more than hitting...its 30 outside and its in a field...and ideas on what i could try i dont wand to have to drive back and forth and drag all my stuff out there to trouble shoot it...thanks for the input

 

1. Test for QUALITY of spark. Should be a snapping, blue spark. Yellow/orange/white indicates a weak spark in which case you should be testing your ignition coil and ignition control module.

2. You need 31 psi of fuel pressure to run that engine. Only one way to know if you have that. Get a fuel pressure gauge on the schrader valve on the fuel rail.

3. Here is a link for testing many things on RENIX (87-90). Good bookmark for all Renix owners.

http://www.lunghd.com/Tech_Articles/...iagnostics.htm

No substitute for testing your way to an answer here....Good luck!

 

Thanks for the info...the ICM and coil are less than 6 months old...I hope they are good

 

Don't assume that. New(er) parts fail way more often than you think.

And when they do fail, it often is in that first 6 months or so. They call that "infant mortality".....