wierd stalling in high heat environments

[mnaemark]

This will most likely apply only to those of you who live in areas when there heat is 105 degrees or higher on a regular basis. I have a '94 and a '95. Both have the 4.0 and are automatic. I use them as daily drivers as my '87 has no a/c and is mainly for offroad.
The problem i am having is that at higher temperatures (103 to 105 and higher) both are stalling out at idle. They will not die just stutter and return to normal idle and then repeat. Both do not do this at night when the temp drops to the 80's - 90's. I did not have this problem last summer but in great coincidence both jeeps have the same symptoms at the same time.
I am pretty stumped here. I would rather just move somewhere cooler but thats not happeneing. If any of you have had the same problem or have any input please let me know

thanks
-mike

Tucson, AZ

 

[Renegade]

i am in the process of finding out this same problem on my '96... fuel pump? CPS, possible vaccume leak....? i dont know...

 

[karstic]

Had a very similar problem today. I was geocaching along a local FS road. Temps were probably in the mid 90's, drivng below 25mph. Some geocaches I let the engine idle other I shut the motor off. Toward the end of the trail the fuel pump started howling like a banshee, then the motor sputtered and died. After letting the Jeep sit for a few the motor would turn over and start, run for 30 seconds to a minute or two then sputter and die.

Luckily I was able to flag down another XJ that came up on the trail behind me. He pulled me out to the highway. After sitting for about 10-15 minutes the Jeep started and I didn't have any problems with the drive home (~50 miles).

I'm thinking that the fuel pump overheated or could it be related to the CPS?