99xjlove

This afternoon I jumped in the jeep and went to start it up and it fired and then died right away. I tried to restart it and nothing. Then If I held the gas on a little ways it would start, and then die if I let off. So then I just held the gas for a minute with it started and it stayed running. I got to my destination and shut it off and went inside for like 5 minutes. I came out and it started fine. Just now it sat for like 2hrs and started up fine. Any ideas?

UNCC_99XJ

Possibly TPS.....mine did the exact same thing when it started going out. Mainly cold start it wouldn't have an idle...i'd have to do the two foot action until it got warmed up, then it smoothed out. But it would do it sometimes warm too.

Another symptom it gave was randomly coming out of 4th gear at cruising speeds....which wasn't a lot of fun on the highway to be running 70mph and have it kick down to 3rd for no reason whenever it felt like it.

No CEL either...

Southern96xj

My '96 was doing the same thing. The check engine light came on the last time, so I had it checked and the error was P0505 or something, the idle air sensor was going bad. Set me back $40, but it doesn't do that anymore after the change.

Andrew_1122

my 96 did that too after i flooded it, and i mean REALLY flooded it. like cycled the key on and off probably 50 times while i was diagnosing a no start.

Southern96xj

P0505 (M) Idle Air Control Motor Circuits SBEC II

That's the exact error I had. It may not be your problem, but the symptoms you described are exactly what I had.

99xjlove

Thanks for the info guys. I don't have any CEL on and the only one that has came on in the last year was for the high voltage imput on the water temp sensor. It was kinda random but I could see how it might be a TPS because I had to engage the throttle manually. I'm headed to work this morning so it has been sitting all night, we'll see if it does it again.

UNCC_99XJ

Thinking back, I did get a code about a year prior to having problems with it for the TPS.....it started running real rough for about 2 minutes then fixed itself....pulled the code for a TPS (don't remember which code offhand) but it had gone back to running fine. Like I said it was almost a year later before it started doing what I described last night.

SeriousOffroad

Got a fuel pressure gauge? Do a leeak down test and a pressure test at idle. Pressure should not fall below 30 psi for five
minutes..

99xjlove

No I don't have one but i'm sure I could put one together fairly easy. Where do you put it in at, since all of th fittings are quick connects?

SeriousOffroad

There's a schrader valve on the fuel rail.