Hey guys! Well I finally got my 89 XJ back up and running after I had my mechanic friend work it over pretty well and fixed a bunch of vac leaks and various small things.. I used it all last summer and through the winter..

Well yesterday he cut out on me.. It was a hot day and I had some long lights to wait at.. I noticed the idle was normal and then it started dropping.. dropped all the way to almost nothing (idle was rough) then it died.. So i threw it in park and got it started again, tried to move through the intersection and it was acting like it was coughing/struggling for air and kinda a muffled exhaust back fire sound from the engine... Anyways.. I eventually got it into a parking lot where a popped the hood and did a quick looksy. I ended up leaving it for a movie and came back that night.. It started just fine and idled like normal.. Drove it home and parked it.. Seemed to run just fine at night or when its in cooler weather.. Test that theory I drove it to work this morning and all was good.. Drove it home today when it was still hot out and I made it but I did notice a little rough idle at the last light..


My question: Does anyone have any ideas of what could be causing this? What should I do first? Im pretty sure its heat related.. anything would help...

Thxs guys/gals!

 

*confirmed irrelevant*

Thanks cruiser54!

 

Might start by checking your fuel pressure when it's good and hot.

 

He has an 89........Doesn't apply.

 

Yup. How much fuel was in the tank when this happened?

 

Not much... less than 1/4 tank..

 

My mechanic buddy tested it when he had it and he said fuel pressure was good..

 

Don't run it that low.

 

Any particular reason it shouldn't be run that low?

 

If there's an in-tank fuel pump, the gas in the tank acts to keep the pump cool. If you frequently run with only a little gas in the tank, the pump isn't being cooled and it causes it to wear out quicker.

 

AnD sucks concentrated amounts of **** up into the pump. Costs no more to keep your tank full.

 

Out running the jeep tonight.. Under heavy throttle and above 45mph the jeep is backfiring.. Any thoughts on what this may be?

 

Clogged cat.