Greetings all. Sorry for the long post but I want to give a good description of my problem. 2000 4x4 XJ. Bone stock. I am ready to start making my next hunting rig but don't want to start until I get this shut off problem solved. I have had the rig about a year. Runs and drives great! But a few months ago I was driving down the road and it shut off. I coasted to the side of the road and it cranked right back up. Every 3 to 5 miles it would shut off and I would crank it back up. Over the next several days it started shut off at idle in the driveway but always cranked right back. I have replaced the coil pack, the Crankshaft Position Sensor (MOPAR), Cam sensor (Standard from O'Reilly) The fuel pump was checked and had perfect PSI under acceleration, at start up and at idle. I ran a new ground from the battery to the wall of the engine bay. After doing all of this it ran great. I ran 3 tanks of gas through it driving the back roads and also the highway. This week it started all over again!!! Shuts off while driving and cranks right back up. Over and over and over the story goes!!! I am stumped. What am I missing here? . Any help or advice will be much appreciated. Thanks for reading my long post.

 

Old fuel filter? There could be junk that plugs up the filter media the longer it runs, then falls out of suspension when it stops running, rinse and repeat. I’ve also had a collapsed filter sock in the tank do this, it would suck itself flat and stop flow after a handful of miles. It was a long 100 mile ride home. Only way to test would be to leave the fuel pressure gauge connected until it stalls again.

What exactly happens when it shuts off? Shuts off like a switch? Or kinda stumbles and stalls like it’s out of gas? Light or heavy throttle, up or down hills, on turns, any difference? Any trouble codes?

 

Shuts off immediately. No stumbling. Normal acceleration up an down hill

 

shuts off immediately. Normal acceleration up hills

 

Just a suggestion - could be a bad connection before the coil pack. Wiggle the connector and wires around a bit when it's running and see if it stalls.

 

I would also check engine ground strap. I had a problem that was a bit similar, but happened very sporadically. After removing the strap and cleaning up the connection point, I never had the problem again.

 

I wonder if it could be a bad ignition switch or lock cylinder. Maybe try wiggling the lock cylinder and see if it shuts off. I had a broken lock cylinder once, but it was the opposite, even though the key was in the right spot, the switch behind it wouldn’t shut off all the way and kept draining my battery.

 

forgot to mention that but I changed out the ignition cylinder lock as well.

 

I will do that thanks

 

My 1st suspect would be the fuel pump relay: costs nothing to check (swap in the fan relay) & a cheap/easy fix if that confirms the cause of the problem..

 

I will give a shot. Thanks

 

Hey! Did you ever get this to work out for you?
I have a Cherokee XJ from 1999 and took it off roading (Didn't go crazy, went slow and steady, with a bit of mud not too deep) and it started doing the EXACT same thing your car did, just shuts off mid drive. When I start it back up it starts fine, and it happens on and off, not all the time. Would love to know if everything worked out for you.

 

Mine did exactly that when my crank position sensor was going bad. Started off as only happening every now and again, then got more regular. Also got to the point where it would sometimes crank for a long time before firing after a shutdown.

I know you said you put a Mopar CPS in it. Maybe look at the wiring harness to see if there is an intermittent connection somewhere. Also, where did you buy that Mopar CPS? Amazon? Possibility of a counterfeit?

 

Do you happen to know roughly how long a new crank sensor lasts? I had mine replaced in 2020, as this was happening back then too and that seemed to have fixed it then.

 

Most replacement parts these days are absolute junk. TEST your CPS.

My Comanche has the original CPS from 1990 with over 200,000 miles.