XJ Engine Dies Randomly

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Jul 17, 2020 | 12:28 AM
  #1  
I have been having an issue with my 1995 XJ 4.0 automatic. The engine will randomly die while driving or sitting at a stop light.

I will be driving, and the engine will just die, even when I have my foot on the gas. Sometimes the RPM will drop to 0 for a split second while driving, and I will have no throttle response, as if the engine is completely off. Then it will suddenly start running again, and carry on as if nothing happened. Other times while driving, the RPM just drop to 0 in a split second and it won’t start back up again for 5-30 seconds typically. Everything electrical is still on and working.

It is not overheating. I have replaced the spark plugs and fuel filter.

I do not believe the issue to be the fuel pump, as it does not sputter at all before the engine shuts off.

I have done a little bit of research and found that similar issues can be caused by a faulty crankshaft position sensor. I wanted to get the opinion of you guys before replacing the CPS, as it can be quite expensive to buy a real mopar replacement.

My questions are:

Do you guys think the CPS is causing this issue?
If not, what else could it be?
Should I waste my time with a $10 eBay CPS just to see if it is the cause of my problems, or should I just buy one from Jeep?

Any ideas or experience would be much appreciated. Thanks!
Reply 0
Jul 17, 2020 | 07:08 AM
  #2  
Grounds, Grounds, Grounds. Take the off, clean them reattach. If you have never replaced your battery and ground cables now is a good time.
Reply 1
Jul 17, 2020 | 07:52 PM
  #3  
I,d try the CPS ,cheap from local stores ,clean grounds are free to to do and do help. I had the same problem and was the CPS
Reply 1
Jul 17, 2020 | 08:45 PM
  #4  
Quote: I,d try the CPS ,cheap from local stores ,clean grounds are free to to do and do help. I had the same problem and was the CPS
I agree it's probably the CPS. But "cheap from local stores" is a great way to join the many who have posted here about aftermarket CPS (and other sensors) being bad out of the box, or only lasting a short time.


The CPS can be tested. If it's bad, spend the bucks and get Mopar. You'll be glad you did.
Reply 2
Jul 18, 2020 | 08:09 AM
  #5  
I got it from NAPA and has been over 7 yrs. Mopar,s way over priced and is probably the same part
Reply 2
Jul 18, 2020 | 01:50 PM
  #6  
It's not the same part, and you are just one person out of thousands. Search this forum alone and you will find many hundreds of posts from people who bought aftermarket and found it bad out of the box, or it died in a few days, weeks, or months.

Glad you have gotten 7 years. You are the exception, not the rule.
Reply 2
Jul 21, 2020 | 10:19 AM
  #7  
I just fought with the same thing with my 1992, mine turned out to be the ASD relay wire to the injectors, but the ground on the side of the block is very important. make sure your valve cover is not leaking onto that ground,
Reply 0
Jul 21, 2020 | 11:00 AM
  #8  
Map sensor next to throttle body. replaced mine years ago as it would shut off at a stop sign or when come to a stop, never did it again after replaced it.
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Jul 25, 2020 | 01:17 PM
  #9  
Quote: It's not the same part, and you are just one person out of thousands. Search this forum alone and you will find many hundreds of posts from people who bought aftermarket and found it bad out of the box, or it died in a few days, weeks, or months.

Glad you have gotten 7 years. You are the exception, not the rule.
And here's another one. After a long thread full of hair pulling, a Mopar sensor solved the problem. Every Jeep board is full of those kind of threads.

This isn't blind Mopar fanboyism. This is the collective experience of thousands of Jeep owners.

Reply 1
Aug 1, 2020 | 02:46 PM
  #10  
Update: Issue Resolved

I went to the Jeep dealer and paid $113 for a new crankshaft position sensor.
I replaced it, which was not too hard. I’ve driven it about 150 miles now without a single issue. So I think it’s safe to say the new CPS fixed my issue. Before, it would happen every time I drove it just about.

For those who view this thread in the future, my 4.0 Cherokee engine randomly died while driving. It would just suddenly shut off while I was cruising down the road. It would sometimes shut off for a split second and start right back up on it’s own and continue down the road. Other times, it wouldn’t start again for 5-15 minutes. The issue I was having progressively got worse. It went from shutting off once every 50 miles, to not being able to make it 100 yards.
Reply 2
Aug 1, 2020 | 04:16 PM
  #11  
Love the feedback!
Reply 0
Aug 2, 2020 | 07:16 PM
  #12  
glad it worked ,does the box have any stickers where it is made.
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Nov 19, 2022 | 12:08 AM
  #13  
Agree mine was replaced in 2010, with an Ebay one, (but here in Aus XJs are regarded as junk ) It is starting the same thing now after 12 years!
***** of a thing to get at tho jeep dealers here would have to order it in? Yeah right where from? Old girl still starts and runs well and next milestone
is 400 thousand kilometres!!
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