2000 XJ with brand new engine, TPS, CrankShaft Position Sensor, new plugs, etc. Computer calibrated by a Jeep Dealer, and Jeep will stall when stuck in stop and go traffic! Any ideas, thanks

 

Any check engine light? If so, post the EXACT codes here for comment.

There certainly are a number of possibilities but the #1 cause of stalling at idle with the 4.0 engine is a marginal battery. And yes, you can have a battery that is strong enough to start the engine, but marginal enough to give the engine management system fits and cause stalling. I can't tell you how many times I have seen and resolved this

Have your battery "load tested". Any parts store will do this for you for free in the hopes of selling you a battery if you need it. Simple stuff first, always.

Other possibilities include the idle air control, throttle position sensor and a dirty throttle body.

Good luck and keep us updated!

 

-So far, things tried, New TPS Sensor installed, New Crankshaft Position Sensor Installed. No codes, No Check engine light, all gauges normal. Jeep is not overheating, or idling too fast. Mechanic wants to try manually adjusting throttle plates. This is a new rebuilt 4.0 straight 6. Started stalling as soon as engine was put in. (Old one blew a rotor)

 

don't forget the camshaft sensor. it will give the same symptoms as the crankshaft sensor, usually even the same codes.

 

Found the reason my Jeep was stalling constantly, the Throttle Motor Module was defective. Once it was replaced, the stalling stopped. The Jeep is now fine.

 

Problem solved! Replaced both Catalytic converters.

Now the Master Cylinder just failed. And they said, why was I worried to hear this Jeep was manufactured on Christmas week.
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