Jeep engine shuts off randomly

A bad crank position sensor usually results in a jeep that will sometimes die while driving or just not start at all. I’m not saying it couldn’t come back to life as you described, just that I’ve never seen/heard about it.

I guess I thought if the CKS was bad what actually happens was it would trigger the ASD to turn off (the ASD is actually what shuts off the car in this case), and I believe it takes the key being turned to START to re-engage the ASD. So that would mean that maybe the interrupt is short enough that the ASD doesn’t shut everything down before the CKS returns to good order? I’m just thinking out loud.
 
I am almost 65 years old. Not extremely tech savvy. I like the Haynes and Chilton manuals. YouTube is great fun to watch. The Haynes manual had the ohm test for the crankcase position sensor. I recently had surgery and it’s hard to get under or in the engine bay…very irritating but I’m working on it

I think you will find the FSM is much more detailed for your specific year/configuration. We have them available for free download in the resources section.
 
  • Like
Reactions: Huckster
I looked at the FSM upon your advice. It looked better for the automatic tranny. I may look at 05, 04 and some other years. I could not find a way to test the sensor in the FSM…replacement
 
A bad crank position sensor usually results in a jeep that will sometimes die while driving or just not start at all. I’m not saying it couldn’t come back to life as you described, just that I’ve never seen/heard about it.

I guess I thought if the CKS was bad what actually happens was it would trigger the ASD to turn off (the ASD is actually what shuts off the car in this case), and I believe it takes the key being turned to START to re-engage the ASD. So that would mean that maybe the interrupt is short enough that the ASD doesn’t shut everything down before the CKS returns to good order? I’m just thinking out loud.

The last time the motor died, I was in traffic and the motor died but the dash remained lit. No start. Turn all the way off with ignition, no start. I was pumping the clutch, shifting gear lever, taking key out. 3-5 min later….cranked up like nothing ever happened. Maybe previously the interrupt was short enough…it was really like a hiccup… then totally fine , smooth running 4.0
 
So I cleaned up the battery terminals and three of the under hood grounds. I started it up in the garage and with the hood up heard some ticking. I was thinking valves until I walked around to the passenger side. The ticking got louder. It was not laughing monkeys, but it was the OPDA ticking like crazy. Put my hand on the top of the black cover and it quietened some. Changed it out today. No more ticking, and it may fix the intermittent hiccup dying/starting as the whole inside was a bit loose and may have been causing the cam position sensor to freak out the control module.
 

Attachments

  • image.jpg
    image.jpg
    710 KB · Views: 19
  • IMG_1385.jpeg
    IMG_1385.jpeg
    656.9 KB · Views: 18
  • Like
Reactions: macleanflood