Engine dies if I dont keep foot on the gas

[Matt2]

Ok, I'm having a really weird problem that REALLY sucks.

I have a 1996 Jeep Grand Cherokee Limted (5.2L V8) and if I dont keep my foot on the gas the RPMs immediately drop to zero and the whole car dies. At first it did this once in a while and I was able to fix it by disconnecting the battery and it seemed to run fine for a while. As time has gone on (started about 2 months ago) this problem is an everyday occurence. Sometimes it will start and run fine, but by the time I get to where I am going, it is back.

I've never encountered anything like this before. I literally have to drive with both feet snd brake while applying as little gas as possible.

I know next to nothing about cars and this beast has 151,200 miles on it. Ran perfectly until this started about two months ago.

Any ideas? Is this going to be big bucks?

 

[SarcasticDwarf]

I had a similar problem (though the battery had nothing to do with it). In that case the throttle body just had enough gunk on it that it was causing those exact symptoms. Google it. It should take you maybe 10 minutes to clean.

 

[Engineer]

Originally posted by: SarcasticDwarf
I had a similar problem (though the battery had nothing to do with it). In that case the throttle body just had enough gunk on it that it was causing those exact symptoms. Google it. It should take you maybe 10 minutes to clean.

That would be my guess also. The most likely reason that it ran better when he disconnected the battery is that the cars computer reset itself and ran a different mixture until it learns again. Once learned, I assume the problem started again.

 

[Matt2]

Cool, thanks guys, I'll check it out.

SarcasticDwarf-

So this exact thing happened to you? Like, even if you were driving, if you let your foot off the gas it died on you right then and there?

 

[Killrose]

Make sure you dont have a vacum leak somewheres. Also with 151k you could have quite a few problems. When was the last time it had a set of spark plugs, cap and rotor? Does it run ok at hwy speeds? Could be some junk in the idle circuit, ect.

 

[imported_hscorpio]

I had a very similar problem with an old s10 with about 160k miles on it. It turned out that the EGR valve was full of black junk. I took it off and cleaned it really well then the truck ran good again.

 

[SarcasticDwarf]

Originally posted by: Matt2
Cool, thanks guys, I'll check it out.

SarcasticDwarf-

So this exact thing happened to you? Like, even if you were driving, if you let your foot off the gas it died on you right then and there?

Yup. A good indicator of this problem is the RPM indicator (although this is not always the case). If you let your foot off the gas and the RPMs drop, bounce up a bit, and go to 0, then it should be the above mentioned problem. Just go ahead and clean it, anyone can do it in 10 minutes.

 

[JasonE4]

I had that problem and it was because the distributor went bad. However, I don't think unplugging the battery would help at all if it was the distributor.

 

[compuwiz1]

Idle control solenoid, perhaps?

 

[exdeath]

Maybe the battery was just coincidence? *shrug*

Might as well check the easy stuff first; fuel pressure, fuel filter, fuel pump, etc.

Sometimes when a engine requires excessive revving and throttle to stay afloat its a fuel supply problem. A clogged filter for example can be overcome with excessive throttle that drives the fuel pressure up enough to force it through, but it will barely trickle at idle and stall.

Usually the dead give away for fuel pump is when someone complains they have to floor it as soon as it turns over or it will die right away... ick!

 

[Pacfanweb]

Originally posted by: compuwiz1
Idle control solenoid, perhaps?

What I'm thinking. Could be other stuff, but this is the first and most obvious thing that causes this sort of problem.

 

[newmachineoverlord]

OK what did this problem turn out to be? I'm having a similar intermittent problem with a 1989 oldsmobile cutlass supreme. It has also started (yesterday) running unevenly at low speeds, sort of jerking a bit. I haven't tried disconnecting the battery.

When it first died I took it to a mechanic and they couldn't get it to reproduce the problem, but then it didn't have the uneven, jerky running at low speeds yet. The only times it has died I had the AC on. They said it was most likely the idle control solenoid. How much do those cost anyways?

 

[krunchykrome]

sounds like a problem for Keanu Reeves

 

[halik]

Dirty throttle body (less likely) or idle control valve (most likely) or crank position sensor (if you have a CEL)

 

[halik]

Originally posted by: exdeath
Maybe the battery was just coincidence? *shrug*

Might as well check the easy stuff first; fuel pressure, fuel filter, fuel pump, etc.

Sometimes when a engine requires excessive revving and throttle to stay afloat its a fuel supply problem. A clogged filter for example can be overcome with excessive throttle that drives the fuel pressure up enough to force it through, but it will barely trickle at idle and stall.

Usually the dead give away for fuel pump is when someone complains they have to floor it as soon as it turns over or it will die right away... ick!

Umm it's the fuel pump crates that pressure and it doesn't vary with RPMs... the only thing that changes with rpm is the fuel injector pulse.

 

[zixxer]

I also bet clogged EGR valve but it sounds like the entire thing is more than ready for a major tune-up.

 

[bruceb]

This thread is over 1 year old ... by now the OP either fixed the issue or got rid of the car .. he hasn't been back to the thread in a long time.

 

[exdeath]

Originally posted by: halik

Originally posted by: exdeath
Maybe the battery was just coincidence? *shrug*

Might as well check the easy stuff first; fuel pressure, fuel filter, fuel pump, etc.

Sometimes when a engine requires excessive revving and throttle to stay afloat its a fuel supply problem. A clogged filter for example can be overcome with excessive throttle that drives the fuel pressure up enough to force it through, but it will barely trickle at idle and stall.

Usually the dead give away for fuel pump is when someone complains they have to floor it as soon as it turns over or it will die right away... ick!

Umm it's the fuel pump crates that pressure and it doesn't vary with RPMs... the only thing that changes with rpm is the fuel injector pulse.

Returnless. Introduced on this model in 1993.

Not only fuel pump, but FRPS (fuel rail pressure sensor) which is the electronic equal to a regulator in a ECU modulated returnless system.

I just try to mention things that haven't been mentioned yet rather than repeat the same possible solutions that 10 other people have posted.

Fuel pressure during the problem is one of the easiest things to check and rule out fuel system problems from tank to injectors before you start taking apart the intake, IAC, EGR, or starting the impossible hunt for vacuum leaks.

Also reading codes or a data log that shows trims and commanded AFR and MAF/O2 readings to verify a vacuum leak before you start taking things apart. There are many diagnostic codes that can be logged regarding mixture and fuel system that do not trigger a CEL.

 

[Bignate603]

I had a similar problem on an old cadillac. It was caused by a short on one of the battery leads. Every once and a while a worn spot of the battery lead would contact the frame and short out. If you didn't keep your foot on the gas the voltage in the electrical system would drop enough that the car would turn off.

 

[TurtleJack]

So this just happened to me. I have a Jeep Cherokee as well. 1992. My battery died two days ago and I got a boost but it stalled immediately after taking my foot off the gas. I then started it again and revved it for awhile but as soon as I took my foot off the gas it stopped. Without having the cables hooked up it doesn't start at all. Seems something is going on with the gas flow. I've been boosted at least 3 times in the past two months because my battery dies and I'm an idiot who leaves the radio going for about ten minutes. My gauge doesn't seem to indicate my battery is low but aside from this I've been boosted successfully until now. I'll take it in but I don't want to have them logging in hours trying to figure out the issue either. Although it doesn't seem anyone has a definitive answer here. But I hope with the answers given it narrows it down for us.

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Thread locked because necro post reposted in new thread, here.

Harvey
Senior AT Mod/Admin