I have a 2000 xj with 4.0 the other day while on the freeway going up a long grade my Jeep chugged a Cokeco times backfired and then quit. I pulled over checked under hood for loose connection didn't find anything noticable. After only about 2 minutes the car started I got about 2 miles further it did it again pulled over for just a few minutes and it started again this time I got 10 miles went through a drive through and while idling it just died. It through the cpk code the first time I reset it the other two times it didn't throw any codes.I had to push it out and I took about 10 minutes to start. I've put about 150 miles on it since with no problems. Things I have replaced prior to this problem....TPS, camshaft position sensor, crankshaft position sensor, removed and cleaned NPS, ..............Any ideas

 

That is classic crank position sensor. Fails when it gets hot and works fine when it cools off. What brand sensor did you use as a replacement? OEM Mopar is by far the most highly recommended. I have used Echlin from NAPA with good success. I wouldn't trust anything else.

 

Yes I have replaced it twice with the Napa brand

 

And the first two times it was only of 2 minutes. I wouldn't think that was enough time to cool down.

 

My '00 would stall out as soon as it would reach operating temperature. And in most instances restart immediately. It did start to get progressively worse from that point on though. Replaced the CPS with a Mopar one and been fine ever since.