My wife has a 1997 ZJ Limited and the thing won't stay running at idle. I can rev it up, but as soon as it comes down to idle...it shuts off. I can restart it, but dies. If I keep it running for a few minutes, it stays running.
I am assuming that it could be the idle control valve.

Has anyone else had this problem and what solved it.

Thanks for the time.

i think you mean her ZJ...93-98 Grand Cherokees were ZJs, 99-Present are WJs..As for the problem..im not exactly sure, but it MIGHT be the O2 sensor??? A friend of mine had the same problem with his Ram with the 5.2...that was the problem with his...Hope this helps..Like I said, im not sure..that was just his problem

Brandon

could be the O2, could be the IAC motor(idle air control) could be the MAP sensor(manifold absolute pressure. located on the TPS for your engine). hell, could be the fuel pump but I doubt it. most likely a sensor. got a check engine light? it may tell you whats wrong.

yup.. could be lots of things.. what codes is the ECU throwing? ya know... that'd be the smart place to start. ;)

I'd put my money on the battery. My mom's ZJ exhibited VERY similar symptoms and a new battery fixed it all.

Originally posted by ItsaJeepThing95
I'd put my money on the battery. My mom's ZJ exhibited VERY similar symptoms and a new battery fixed it all.

actually this sounds more like the problem. take it to an autoparts store and have em load test the battery(if you dont have a load tester already).

My WJ pulled some crazy shit like that with a battery on it's way out.

Freaking weird stuff...

Otherwise IAC, TPS or MAP. I can't see it being an o2 sensor.

Well, if it was throwing a code...I wouldn't have posted the question. I will have the battery checked, but sounds like a weird
problem to cause the thing to shut off at idle, but run if you keep you foot on the gas.
When this originally happened, sprayed carb cleaner in the throttle body and it stayed running. That is when I stayed home and did a cap,rotor,and plugs. It ran great, but after a few days, it started to act up again.
Matter of fact...when I was tring to back up to my car trailer, I would try to feather to gas, but it would kind of surge and almost shut off. Than at times, it feels real sluggish.
I am almost starting to point at the TPS more than anything, but will check the battery and run a code reader on the Jeep.
This is my wife's and I first Jeep product and have had these little things happen...not getting a good feeling about it. The ZJ is in mint condition, but these problems are getting tiring. It has 112000 on the OD.

Thanks for the time and help

Shagnaz,
Your latest reply leads me even more towards the battery. When this happened to my mom's ZJ the battery was so dead that it couldn't store any codes. I ended up replacing the MAP sensor, and that was like a bandaid for the problem. It helped for a couple days (no idea how!) but then the old problem reared its head. I grabbed the Optima out of my ZJ and tossed it in my mom's, and bada bing it worked just fine and has ever since.

BUT...it turns over just fine. I have a code reader that I am going to use to scan for any codes. Then I will go to the auto store to have the battery tested.
I guess I'll see today. I will post if I find anything.

When was the fuel filter replaced????

Originally posted by Shagnaz2
BUT...it turns over just fine. I have a code reader that I am going to use to scan for any codes. Then I will go to the auto store to have the battery tested.
I guess I'll see today. I will post if I find anything.

My '00 had 12.0 volts and did that crap, started but would die and it could do it over and over. Alternator and ECM were fine.

Oh and JU is a better place for this info, the GC forums are not technical per say but they have discussed about every problem and resolution and often timelines to predict it.

ECUs on 318s are notorious for going bad. We sell them almost daily at CarQuest.

May want to check the TPS. You can check it with a voltometer, I'm not sure on the exact voltage but it should increase with throttle and i think idle is around 5v?

If this were an ECU, it would most likely crap out while driving down the road... or after it gets warm (most electrical componens start to show signs of a slow death with heat). It does sound like a battery. ZJ's are very sensitive when it comes to batteries. Try taking a battery out of your other vehicle and see how it acts then. Even a battery that shows to be good through a load test can be bad. Another thing to look for with a battery going south is if you VIC or your radio have been resetting themselves lately. HTH.

To check the TPS, backprobe the center wire on the connector. The voltage should be .6-.9 at idle and then increase gradually to around 4.5-4.8 at WOT. I would also suggest changing the fuel filter and IAC at the same time. Just for the heck of it, check to see if you are getting fuel. Can you hear the pump turn on when you listen against the gas tank?

I took it up to a battery store and they did the test on the batt. and alt....both were fine. Showing 13.5 from the alt and 11.5 to 12 at the battery. I checked for codes...nothing.

Fuel filter...it runs fine at high rpms. Usually if the filter is getting clogged...it only runs at idle.

I cleaned the ICV(Idle control valve) and the butterflies last night.

If the problem happens again, I'll just grab one of my yellow tops out of the blazer.

I hate these problems

:mad:

Just an FYI Shagnaz, somehow the battery on my mom's ZJ tested out okay when this happened to hers.

Originally posted by Shagnaz2
I took it up to a battery store and they did the test on the batt. and alt....both were fine. Showing 13.5 from the alt and 11.5 to 12 at the battery. I checked for codes...nothing.

Fuel filter...it runs fine at high rpms. Usually if the filter is getting clogged...it only runs at idle.

I cleaned the ICV(Idle control valve) and the butterflies last night.

If the problem happens again, I'll just grab one of my yellow tops out of the blazer.

I hate these problems

:mad:

Thats not necessarily true about the fuel filter. I've had those symptoms happen a few times and changing ou the few filter fixed it. ofcourse thats an easy fix on '93s- some '96s since the filter is outside the tank. Inside is a PITA.

WELL...I replaced the battery, but problem is still there. I guess I am going to change out the idle control valve.
Seems like if the butterflies are closed...it chokes out.
I will take any suggestions, but will keep y'all posted what I do
to fix the problem.

Thanks for the time

I agree w/ the IAC. My bro had the same thing happen to his Ram w/ the 5.2. Would shut off at idle, but above idle it ran fine. Good luck.

Replaced the IAC last night, so we'll see what happens this morning when the wife goes to start it.
Will keep y'all posted

When mine did that, it was the TPS.

ZJ's run nororiously shitty with a weak battery. Mine wouldn't even hold idle at all.

That being said, why the fawk are you posting this here? Might want to take it to JU or NAGCA

I'm too scared to post this kind of shit here :D :flipoff2: