mike1966

my son has a 96 and it developed a problem and i wanted to know if anybody else had the problem and what you did to fix it.
What is is/was doing is that he would be driving down the road and when he went to stop it would die. But it would start right back up. Well, it did it again today. And when i went out to look at it i tried something. I would start it and with it in park, rev it up to like 2000 rpms and hold it for like 10 seconds or so, maybe a little longer. As soon as i let off it would die, but start right back up. And while it was running it ran great...wouldnt hesitate ir miss or anything. just when you sustained a higher rpm and then let off it would die.
Soooooo, i started by changing the fuel filter. the old one was on backwards btw, so i thought the new one would at least help. It still did it after the new filter. So for some odd reason i tried something that i did on his 96 mustang he had. I disconnected the positive battery cable for about 10 mins to see if it would reset the computer (thats what it did on his 96 mustang) and when i started it back up it wouldnt die anymore.
Im sorry this post is so long, but i wanted to explain what it was doing and what i did and its not doing it now, and see if anybody else had this problem and what they did to fix it

thefirebuilds

I know NOTHING about jeeps, but that is typically caused by a vacuum leak or an intake solenoid that has gotten gunked up.

mike1966

well, the 96 mustang gt my son had wouldnt idle at all. You could start it and rev it up, but as soon as you let off the pedal it would die. So i started googling it and a few posts said to reset the computer and to do that you unhook the pos cable for about 10 mins. I thought i would give it a try on this jeep, and i dont know if that actually reset the computer or what i did, but its not doing it anymore. But i really would like to know what i did to fix it LOL

mike1966

i sure hope somebody has some input on this

mike1966

wow...i guess im the only one that ever had this happen

thefirebuilds

look across your vacuum lines for cracks. There should be small tubes running from the Valve cover to the throttle body area. On most cars ive worked on there is a solenoid on the TB that will get stuck over time. Otherwise vacuum lines can crack or come loose, especially after offroading or an accident.

4.3L XJ

If it won't stay running, I would check the Idle Air Controller. It can get sticky and not compensate for changing conditions, like letting off the gas rapidly. You can try to clean it. Many times that is all it needs.

Typically on fuel injection motors, a vacuum leak will cause it to idle fast.

thefirebuilds

if its between the mas/maf and TB, yes, but a vacuum leak after that point will make it not run or stumble. unplug the PCV for instance by pulling it out of the vc and the truck should stop.

I didnt know for sure the Jeep had an IAC, but definetely the first thing I would check. A little carb cleaner can loosen the gunk up some.

96xj4x4

not to sure if this helps you to much but awhile back my jeep was doing a similar thing when i had an the engine at a load and when i backed of (like for a stoplight or to turn) she would just shut down on my but it would fire back up right away, additionally it was also idling rough and very low...this fix ended up being the tps (throttle position sensor)

Vindicator9000

Yeah my Civic had the exact same symptoms. Turned out to be a dirty throttle body / TPS sensor. It's not a Cherokee, I know, but everyone else seems to be indicating the same sort of fixes for this problem that worked on my car. I'd start with the throttle body and TPS.

Cleaned out the inside of the throttle body really good with carb cleaner, and it stopped right away.