tyeayo

Soooo...
It seems to be fixed after a battery reset, than after awhile we get the rough idle than it dies when at a stop in drive.

My wife and I have owned a 2001 Jeep Grand Cherokee Laredo 4.0 for the last 6 or so years and it has been fairly reliable. I have had the usual issues (coolant relay replacement, ran relay replacement, rotor warpage, etc) but nothing beyond my realm or ability or comprehension. But now we are into the "stalling intermittently" phase and it has me stumped. It will start to idle rough at stops and than die. I have reset the ecu by unplugging the battery, and that has cleared it up each time, and it would not be an issue again for several months, however, it is becoming more frequent as of late. I am not getting any codes when it happens, nor any CEL lights. The throttle body is clean and shiny and I tuned it up with new plugs about a year ago.


I have researched other stall problems and no one has made mention of the battery reset working for them, so I am curious as to what it may be that the battery reset is resetting and causing it to work fine.


Appreciate the input fellas

dave1123

It's possible your idle air control (IAC) is at fault. It's possible the piston is sticking in the bore occasionally. Take it out and inspect it for deposits and wear. It costs about $50 so I wouldn't replace it unless it shows that it is faulty, but it can be cleaned.

Welcome to CF! This is just my opinion as to where to look for a problem. Why resetting the PCM fixes it, I haven't a clue unless it pulls the piston out of the bore. Those deposits get sticky when they get hot. NAPA Brakleem seems to work to clean it.

My WJ seems to stumble momentarily for no apparent reason and it is totally random, but only continues for about 1 to 2 seconds. How can you trace something like that? This had only started in near 0 weather, so I might have a sticking IAC also. It's been way too cold to work on it in my driveway.

I hope this helps you.

tyeayo

Yeah, the iac is a big one that pops up alot when looking for a fix. I have checked that and cleaned it so that's not the problem....I just don't friggin understand

dave1123

Talking to you may have jinksed me! My WJ ran flawlessly last night for 4 hours, then I stopped for some cigs. When I restarted it, it shook very badly and wouldn't smooth out. I shut it off and started it again. Like it never happened! WTF? Jeeps are like that, yeah they are.

tyeayo

So for the last couple of weeks, my wife has been running nothing but mid grade fuel and there has been nary an issue....So strange