Symptoms
The engine cuts out without warning, often warm and sometimes at highway speed. It may restart after sitting, or crank but not start. NHTSA's complaint file holds dozens of ZJ stalling reports in which the crankshaft position sensor was replaced, sometimes more than once (e.g. ODI 878399, 10460757).
The fix, step by step
- Read any stored codes first (1996–98 trucks are OBD-II).
- Then inspect the sensor's harness for chafing and heat damage.
- One 1995 owner traced his stalling to a broken front motor mount that let the engine tug on the crank-sensor leads until they chafed through and shorted (NHTSA ODI 784679), so check the mounts too.
- If the wiring and mounts are good, replace the sensor.
- Stalling has other causes, including a failing fuel pump (see below), so confirm the diagnosis before you buy parts.
Tools & part numbers
- OBD-II scanner (1996–98)
- multimeter
- sockets and extensions
- flashlight
Where to buy the parts
Crown 56026921 crankshaft position sensor, 1994–96 ZJ 4.0Quadratec ↗Amazon ↗
Crankshaft position sensors for other years and engines (RockAuto catalogue)RockAuto ↗
Motor mounts for 1993–1998 Grand Cherokee ZJQuadratec ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Jeep Grand Cherokee ZJ parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.