Sometimes my jeep will start and run for a while and other times it's will shut right off after it starts. Also sometimes happens when I'm driving and it will start chugging but I will just rev it up and it will be fine? Is it the fuel pump or something else?

 

Sounds like it could be a bad fuel pump. You want to verify fuel pressure at the fuel rail

 

Well the fuel pump is working if u can rev it up and be fine

 

IAC could be the cause...

 

U should give everything a good once over and cleaning before throwing parts at it

 

It will let you rev it sometimes but other times that will also kill it...

 

It doesn't seem like a fuel pump to me
But I'm not there diagnosing it

 

Alright thanks.

 

Get pressure gauge and test it

 

Doesn't a 96 still have a fuel pump ballast resistor mounted on the driver's side fender well? If the connectors are loose on a ballast resistor or it's going bad, the symptoms will mimmick a failing fuel pump.

 

Hmmm I've never heard of this before. I'll look for this on my 96. What you're talking about would be back by the tank right? Do Renix XJs have this?

 

Renix does for sure. Located on the driver's side inner fendeer near the air cleaner box.

Supplies 12V to pump on starting and then reduces the voltage on Run to keep the fuel pump quiet.

My wife complained that at times her 88 was acting like it die before the fuel pump failed. Me doing what I do, RCBRC, I checked each of the 2 connectors at teh ballast resistor and found they weren't grasping the tabs tightly. Fixed them up and no more problems.

 

I cleaned the iac that didn't change anything. I also took a fuel line off and put it in a bucket turned it on and it would give gas for a couple secs but should it keep running or is it supposed to shut off like that?

 

I think I see what your talking about. I will look at that next.

 

1. No ballast resistor on a 96. 93 was the last year.

2. The ONLY way to test fuel delivery is with a gauge. NO shortcuts. Many parts stores will rent you this tool inexpensively. For a 96, you should have 49 psi, plus or minus 5 psi.

3. Be darn sure all tuneup hardware is fresh. Champion copper plugs gapped to .035, new high quality plug wires, cap and rotor. The importance of good tuneup hardware cannot be overstated.

4. If the above all checks out, it is possible that you are on the front end of a crankshaft position sensor problem.