Sorry I am a complete noob here but I jus purchased a 2000 xj with only 170k miles for 800 bucks. It runs great until its warmed up then jus dies like u turned the key off but didn't turn it all the way. And it won't start back until like 20 min later. It's gettin fuel to the fuel rail but Idk about fire bc it has coil packs. Has new coil packs, plugs Idk what else to I'm lost... and it doesn't throw a check engine light or anything. Any help would be great and sorry posted from phone

 

thermo stat. go buy a 195 thermo. i had the same problem it was running to cold for the computer. and it would run for 10 or so minutes till 210 on the tac. then bam it would die. wait a little while and it would fire right back up

 

You are experiencing "thermal failure". When the suspect component warms up, it fails. When it cools down, it begins to work again.

The #1 suspect here (by far) is the crankshaft position sensor. It is the most common engine management sensor failure on the Jeep 4.0

The odds are very high that this sensor is your problem. A good percentage of the time, a failing crank sensor will NOT set a check engine light.

If you buy one, purchase it directly from Jeep. No lack of threads of people having trouble with some (not all) aftermarket crank sensors. Because it is such a critical sensor, it is well worth the extra money to buy this from the Jeep dealership.

Good luck and check back and let us know how things turn out.............

 

I agree with tjwalker on this one. I had the same issue with my 96' and sure enough the Crankshaft Position Sensor was the culprit. Best of luck to you in fixing the problem!

 

X2

 

thanks that fixed it runs like a dream. now time for a lift... what would be best and cheapest

 

You are very welcome.

There are two groups of XJ 4.0 owners:

1. Ones that have had to replace the crank sensor

2. Others that WILL eventually replace the crank sensor!

If you own a 4.0 engine long enough, you absolutely positively will be replacing your crank sensor. It is a given. Just a matter of when.

 

There is no such thing as the "best" and the "Cheapest" lift. Its either one or the other. All depends on high you want to go. 2 inch for around 200, anything higher then that, and it can get ALOT more to do it right.