I had a similar problem with my 99 classic and had to replace the CPS and problem solved.

 

It wouldn't hurt to water tight the distributor cap a little bit. I've had problems with wet distributors on every one of my 5 Cherokees. I run a small bead of silicone around the sealing face of the cap. What you're describing is similar to what would happen to me although it was usually in deep water crossings that it happened, not hosing lol. Might not fix your problem but it won't hurt anything.

After I sealed the cap canal driving with water up to the windows was no problem.
Good luck on your fix

 

Cps?
Would that be cam or crank?

 

I power washed my engine bay and ran into this problem. Ended up being a little moister getting under the distributor cap. Wipe it out with a rag. Problem fixed.

 

Crank positioning sensor on top left of trans bell housing on an automatic

 

I think you are right, hes sayin that it runs fine till its warm. Sounds like a crank sensor to me, Given the code as well.

 

Trust the code. Is it P1391? Always best to post the exact code here for the most accurate replies. A P1391 could be crank or cam sensor but crank sensor fails more frequently.

It is not unusual to have a crank sensor suffer from thermal (heat related) failure.

 

He never told me the exact code, lts hard to help someone that isnt giving enuf info ik ik..this weekend im taking my scanner and ill find out exactly whats wrong. I believe its the crank but ill test and make sure. Not jus gunna throw parts at it and hope its right.. From reading on this i gather that alot of guys jus throw parts at their jeeps and hope their problems go away... Thats not how we do things