Intermittent stalling

I have recently purchased a 98 Cherokee Laredo that has a problem with intermittent stalling. It doesn't seem to have any pattern to it, cold, warm, idling, at speed, etc. I have searched a few threads and learned a few things to look for. It has an oxygen sensor code and am wondering if that would cause the stalling. Any thoughts?

 

The oxgen sensor tells the computer how much fuel the injectors need to give, so if it is malfunctioning I would think that stalling could be a symptom. Exactly what code are you getting? Their are some members on this site that might be able to expound on your situation.

 

I was getting a code for the rear 02 sensor high voltage. I replaced that sensor and cleared the trouble code. It lasted for maybe 50 miles and came back. I managed to find a donor vehicle and swapped the engine, trans, and exhaust to mine. The CEL went out but the stalling continued. I replaced the fuel tank and pump from the donor and the stalling went away. Dunno what the actual problem was because I tested the original pump pressure and it was rock solid at 55 psi. Anyway, the problem is fixed so now I can finally register the bloody thing.

 

Maybe there was too much trash in your tank and it was clogging up the pickup filter. Glad you fixed it!

 

Fuel pressure was too good to be a plugged filter. I tested it at 3~4K rpm. When the engine would die, it would immediately start back up and revving the engine was sometimes the only way to keep it going. I cannot positively debate the issue though because I have no idea what cured it.

 

Not what I meant. The pickup filter is a plastic screen. My CJ had an old rusty gas tank and I believe that the screen would suck up enough junk that it would lose significant flow and quit. Then all the stuff would fall off the screen and it would start up again and drive awhile and then die again. I am only guessing at this because I can't visually confirm it, but I replaced the pickup tube and screen/filter it still happened and then I replaced the tank an all was good.

 

Dunno Dood, that's quite a reach since the 98 GC has a plastic fuel tank. I poured a few gallons of left over gasoline out of the original tank and there wasn't any debris in it. Something was wrong with that pump and tank combo and I will not spent the time nor effort to figure it out but rust and debris seems unlikely.

 

Ideas and suggestions are just that. Ideas of may be the issue. And suggestions as to what might be a fix. That's what we do here. If it's not the issue with your problem. At least somone tried to help. Just saying...these days with all the tech and sensors and computers. We're all still learning. Back in the day. You had a stalling issue. You changed the gas and air filter. Ya know. Now....theres sensors involved.

With the tech involved with our rigs today. We just need to be open to any remedies out there that might help. Just saying. .

 

Well, the issue continues. About two weeks ago I went to the store to have a bag of green chiles roasted as a birthday present for my friend and the Jeep stalled probably 6 times before I could get out of the parking spot. As long as I kept the engine revving it would stay running. Let it idle and it would die. Usually it restarts easily but this time it was having a tough time starting too. Is the TPS (throttle position sensor) a source of common stalling issues? I now that the TPS on my 95 Ram 2500 would get a bit wonky when it was too hot but it would only let the engine idle slow enough to cause a low oil pressure alarm. It was not an actual source of stalling. Still scratching my head over this one. Here is a list of things done since I have owned it and a couple things done prior.

Replace ignition coil. (prior) Problem persisted.
Full ignition tune-up, plugs, wires, cap, rotor. Problem persisted.
Replaced rear 02 sensor in exhaust. Problem persisted.
Replaced complete engine/trans including ignition tune-up. Problem persisted.
Replaced full exhaust with engine swap.Problem persisted.
Replaced fuel tank with pump. Verified fuel pressure @ 55 PSI before and after tank swap. Seemed to resolve the issue but it has returned.

Going to verify the ignition switch next time I have a chance.

Any other suggestions?

 

Is 98 the 1st year of a distributorless system? That would mean you should have a cam sensor and a crank sensor. One or both may not be working or working intermittently as they do when they start going out. Do you have a Dealer service manual for your jeep. They have trouble shooting guides to follow when having issues like these. They have step by step tests that you can do to narrow down to your problem and the fix. I have one for a 79 cj and a 94 YJ, but neither have a distributorless system so I am limited as to how far I can trouble shoot for your vehicle. Really need access to a 1998 DSM.

 

98 does have a distributor. It is the 4.0 inline 6 cylinder. Just as a process of elimination I think the issue is part of the chassis electrical system since everything else attached to the engine has been replaced. The coil was replaced by the previous owner and I did not keep that when I replaced the engine but everything else was swapped out. I made sure the engine ground cable was securely attached so I am confident that is not the problem either. The fuel tank and fuel pump have been replaced with used units so it could still be a bad fuel pump but those are not typically intermittent. I dunno. Since the problem is persistent I must be also.

 

This is like a bad movie with no ending in sight.
Hope this all works out for ya cjsdad.