88 MJ runs great "BUT" it won';t restart why?

[Submariner]

88 MJ with a 4.0 in it.  runs really good with 286K on it.

 

BUT after you drive it for a while and turn it off, It won't restart.  

 

Give it 5 to 30 minutes then it will restart and runs fine.

 

Won't do it every time, drive it for 5 miles or 20 miles don't matter.  3 out 0f 4 times it will restart then it won't.

 

This would not be a problem if I was bar hoping but i got other things to do.LOL

 

What are your suggestions or comments.

 

right now I have ran out of ideas other then pulling the fuel tank and put in a new fuel pump and change the filter.

 

Thanks

[87MJTIM]

Some other members have commented on "heat soak of the CPS."  When the engine compartment is hot, the engine will not start until it cools off some.

 

It has not happened to me (knock wood), but others have had this problem.

 

Have you tested the CPS with a  DVOM?  Check out Cruiser's Renix tips on testing it.

[MiNi Beast]

Fuel pressure regulator, check for leak down. Cycle key on and off to prime and see if that helps. 

[cruiser54]

Have you completed Tips 1 through 5 yet? 

[Submariner]

I have not done c101 yet.  I have done some new ground but not all yet.  I was going to wait until I replaced the engine, tranny and added a transfercase and do all of while the engine is out.  I think maybe I will have to do it sooner then later now. lol

 

I have changed the ecu from an 88 model year to a 89 model year.

[cruiser54]

I suggest completing those Tips now. super easy.