Dies when hot

[Euclid]

Jeep dies when it gets too hot

Is there a temperature controlled cutoff switch somewhere?
My temp guage always reads under about 210.
Sometimes, especially on hot days, the jeep will just die.
Sometimes it will run fine but won't start when I crank it back up.
If I let it set a while, it starts up fine.

What should I start looking at?
I initially thought it was the coil because I didn't think I was getting spark but maybe I am. I just replaced the plugs/wires.

Thanks

 

[GSequoia]

Sounds like a Crankshaft Position Sensor (CPS) to me.

 

[Euclid]

I'm up in the air between CPS and over-heating coil.
My problem is strictly heat-related. Only happens when it's very hot.
Seems to me that CPS would happen all the time.
Thoughts?

 

[GSequoia]

I'm up in the air between CPS and over-heating coil.
My problem is strictly heat-related. Only happens when it's very hot.
Seems to me that CPS would happen all the time.
Thoughts?

I've never seen a coil fail and I've had a lot of Jeep problems!

The first time I battled a CPS (In fact that was the issue that made me find waaaaaay back in '99) was what you describe. The Jeep would cut out when it was hot, I'd let it cool off and it'd work again.

 

[Euclid]

Are there any good write-ups for CPS installs?
Thanks!

 

[codyj86]

really it could be any electric device that is nessesary for the enigne to run. as soon as that component heats up, it is ohming out. meaning it's causing either to high resistance, or opening the circut completely. i would stick to the common issues, but if you want to test parts, get some schematics and use a heat gun or the oven (don't let the wife see, i know mine doesn't like it) and check resistance when it's hot.

oh, and i had a coil go bad. just fyi.

 

[downunderxj]

I have also had this problem recently, engine would be hot and just suddenly stop on me. I also had two times when I had been climbing hills and turned the jeep off to enjoy the view and then it would take 20 minutes or more before it would fire again, would crank fine.
After reading a number of posts on (and other Jeep forums) I replaced the Crankshaft Position Sensor and have been out on quite a few trips since with no further problems.
The CPS is located very close to the exhaust.

Have a look at http://www.naxja.org/forum/showthread.php?t=942941&highlight=crankshaft+position+sensor+replace, and use the Search, this topic has been discussed a number of times.
Good luck
Ian

 

[Saudade]

http://autorepair.about.com/library/faqs/bl077g.htm

 

[karstic]

Are there any good write-ups for CPS installs?
Thanks!

It's really not very difficult, two bolts and a connector, you need a few extensions and a wobble joint helps.

One way to help determine if it is the CPS is to cool off the CPS with water after you have the shut down symptom. That will sometimes cool the CPS enough to allow it to function properly.

 

[IslanderOffRoad]

My CPS would only die when I ran the Jeep for a while and it got warm.

 

[Euclid]

For future reference, a new coil did not fix my problem.
A new CPS did fix my problem.

 

[crystalship1]

For future reference, a new coil did not fix my problem.
A new CPS did fix my problem.

Always appreciate an update.

Congrats.!!!!! :yelclap:

 

[Euclid]

From reading posts I was pretty scared about replacing the CPS.
That thing was easy! Drop the crossmember, I had the new one hooked in less than half an hour... 2' extension and a swivel socket and you're golden.