Thank you in advance for your help. I have a 1993 ZJ with the 5.3L V8. Here is the problem. Every time the Jeep has sat for a while it cranks longer before it starts, when it does start is idles low, misses if you push on the gas it backfires out the air cleaner, then after a few minutes it revs up by its self and runs great. Every once in a while it doesn't do it but that is not very often. it kept dying on me also and I sat there restarting it until the battery was dead, and had to call work and tell them I am stranded. I replaced the fuel pump 24 months ago, replaced the O2 sensor a few months back, and I replaced the idle control sensor. Thanks again for you help, I need to get this fixed a.s.a.p. Also it is not throwing any codes.

Update, I just got it started. It did the spitting and sputtering thing then leveled out like it normally does, but now it wants to dies every time I touch the gas and backfires through the air cleaner even though it is idling well. Please help Thank you

 

Try warming the PCM with a hair dryer and see if it makes a difference. We seem to be having a run on this problem now that it's getting colder.

 

Thank you, I will give that a try

 

I tested the fuel pressure and it was 4psi. So I replaced the fuel pump, problem solved

 

Bingo! It was probably just the pressure regulator on the pump, but it isn't serviced separately.