I have a 2002 Jeep Grand Cherokee with 207,000 miles that has recently begun stalling while driving. Typically stalls at rest or when coming to a stop, and for a time it would re-start without issue. More recently it won’t start readily after stalling, but will eventually start with enough key-turning persistsence. The check engine light comes on only after stalling and not restarting (but was not on previously), and often shuts off after a few miles of smooth running. I took it to my local mechanic who ran the computer codes and reported a malfunctioning cam shaft position sensor (i question if this was the casuality of other problem), which they thought was the source of the stalling, but after replacement it is stalling more than ever. It seems like the local mechanic group won’t diagnose anything in this high mile Jeep without a computer code and I am reluctant to bring it back.
Any thoughts on the cause of the stalling / starting issue? I may be way off but was concerned about a clogged fuel filter or fuel injection problems. These ideas were not entertained by the local mechanic group… All feedback appreciated!
Vehicle Details:
2002 Jeep Grand Cherokee Laredo
4.0L inline 6
207,000 miles
Regular maintenace, most miles highway (2 owners)
All parts stock
Did they replace the camshaft synchronizer? You need to find a good independent mechanic who will find the cause of the malfunction. Computer codes are great but they do not encompass all of an engines failures. Have them test the fuel pump pressure first then move on to troubleshooting the fuel injectors, ignition coil and the ignition system kit. The “mechanic group” sounds like they are lacking in the mechanic skills department. There are a myriad of engine malfunctions that will not trigger a CEL. Even if you do get a computer code it will only give you limited information about the true fault. You need a real mechanic to find the malfunction.
The next time you feel the engine is about to stall, with your left foot firmly on the brake pedal slightly step on the gas pedal. If doing this prevents the engine from stalling the problem is with the Idle Air Control circuit. This can be caused by a dirty or defective Idle Air Control valve.
The first thing to try is remove the Idle Air Control valve and clean it along with the idle air bleed port on the throttle body with an aerosol throttle body cleaner. Reinstall the IAC valve to if this cures the stalling. If not, then the IAC valve may be defective and requires replacement.