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98 jeep grand cherokee laredo 4.0 straight six 4x4
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!ZJ (93-98), WJ (99-04), WK (05+)
All ZJ/WJ/WK specific tech questions asked here!
96-98 are notorious for having ECM connection issues that cause random stalling. A quick easy test is to wiggle the connectors while the engine is running. If it stalls or stumbles you have an ECM issue.
Pull the three connectors off and spray them with electronics cleaner and allow to dry thoroughly before reattaching. A trick is to wrap wire ties around the connector and ECM case forcing the connector to stay pressed against the ECM more securely.
The ECMs are also known to develop internal cold solder joints, the wire ties won't help if that's the issue. You can either attempt to repair the ECM yourself or replace it.
Or, it could also be the CPS. Not an expensive part but a real pita to install.
96-98 are notorious for having ECM connection issues that cause random stalling. A quick easy test is to wiggle the connectors while the engine is running. If it stalls or stumbles you have an ECM issue.
Pull the three connectors off and spray them with electronics cleaner and allow to dry thoroughly before reattaching. A trick is to wrap wire ties around the connector and ECM case forcing the connector to stay pressed against the ECM more securely.
The ECMs are also known to develop internal cold solder joints, the wire ties won't help if that's the issue. You can either attempt to repair the ECM yourself or replace it.
Or, it could also be the CPS. Not an expensive part but a real pita to install.
I'm trying to think of other things...
I seem to recall a user posting (long ago) that their downstream O2 sensor wire had come loose and was resting on the exhaust and had become melted/frayed and would intermittently ground out to the exhaust pipe causing stalls.
You may want to look at that and any other wiring near the exhaust. Also maybe even give your wiring harness, in general, some wiggling while the engine is running looking for stalls or stumbles.
I'm trying to think of other things...
I seem to recall a user posting (long ago) that their downstream O2 sensor wire had come loose and was resting on the exhaust and had become melted/frayed and would intermittently ground out to the exhaust pipe causing stalls.
You may want to look at that and any other wiring near the exhaust. Also maybe even give your wiring harness, in general, some wiggling while the engine is running looking for stalls or stumbles.
Have you replaced the crank position sensor?
it does it at start up and strong smell of old fuel. Backfire out intake. That might help. No idle problems.
See if you have any wobble in your distributor shaft and any other obvious damage to the cam sensor inside the distributor. Is startup the only time it stalls and backfires, or does it stall while driving?
I'm sorry, but you've had this problem for 3 years so just about anything could be a cause.
02-11-2018, 07:09 PM
98 jeep grand cherokee laredo 4.0 straight six 4x4
