89 Cherokee 2.5 engine quit unexpectedly, start intermittently and again died unexpectedly

[manaswee]

The problem began a week ago when, without any prior indication, my 89 Cherokee with 2.5 motor died in the middle of busy traffic. After it was towed home, it started up so easily as if nothing had ever happened. I took the same Jeep out the next day, it ran about l2 miles then it quit; I had to have it towed home for the second time. My hunch initially pointed to the fuel filter so I replaced it. It must be a mere coincidence, as right after I replaced the fuel filter, the car started right up and ran as powerfully as usual. I was wrong. The car ran only six miles and expired. I had it towed home for the third time.
After all theses incidents, I had become very apprehensive and virtually idled the car. Worse yet, I had tried to start day after day, the motor will crank but there was no sign of life. I began to "play mechanic" by checking the source and trace of fuel supply. The fuel aspect checked out OK. I took the ignition coil and the ignition control module (both are two pieces in a part bolted together) to Autozone to have them checked. The Ignition Coil checked out good but there was no tool to test the ICM. Disappointed but remained enthusiastic. Ignition Coil and Ignition Control Module are mechanically easy to replace, but cost a lot more than Crankshaft Position Sensor which was a lot more difficult to reach but only costs a mere $28.00 Not really knowing what I was doing but being full of enthusiasm, I decided to look for the CPS(that dragon fly looking thing on the transmission bell housing; location 11 o'clock). It had been untouched for 2l years during the entire 250,000 miles of loyal service. The two 11 mm. bolts not only came off almost without effort, the whole unit was covered with hardened black soot. As soon as I finished installing the new CPS and plugged the necessary wiring connections, the car started right up. The problem was solved. I did not really think the problem was with the CPS, but surprisingly it was!

[fredjacksonsan]

Great story....the 4.0 has an issue with the CPS and there are numerous threads about it; so when I started reading it sounded awfully familiar.

Glad you're back on the road.