Jeep Cherokee Limited Crank, No Start
Hi! The Jeep has periods when it will not start for a couple days (cranks fine but won't fire), then it will mysteriously start again. A friend suggested that it may be the CPS - I checked it has 200 oM - when I'm cranking by hand it's little bit changing - it should be OK. But again, wouldn't this also effect the engine during those times that it was running?
This problem occurs during rainy and sunny weather so I don't think it's a moisture or water intrusion problem. Is there any part of the ignition system that only affects starting that could be causing this problem?
- 1989 Jeep Cherokee Limited
- 4.0 liter
- Automatic transmission
- 170,000 miles
I found some forum where some guy had the same:"I am having the same or similar problem with my wifes 1990 Cherokee. I have found a place that tests the ICM. It may take a while to find a place in your area. I suggest you go in person and talk to the people in your better parts stores.
I have been unsuccessful so far in finding the fault. My ICM has been tested twice and passed both times. I have power to the ICM and the coil checks within parameters. This has been a very frustrating problem for me. I'm about ready to drive it off a cliff and call it a day. Good luck."
So my question is; what is the reason of that?
Thanks for help...
This was a widespread problem for Chrysler and they issued a couple of TSBs to address the problem. The first was:
1989 MJ & XJ Bodies
4.0L No-Start, Hard Restart, or Engine Die-Out. Vehicles Equipped With Automatic Transmission Only.
Date: December 29, 1989 No.: 18-57-89 (C18-23-9) P-14
Body Code Legend:
MJ - COMANCHE (RWD, 4WD) XJ - CHEROKEE/WAGONEER (RWD, 4WD)
Some 1989 vehicles equipped with the 4.0L engine and automatic transmission may experience an engine no-start, hard restart, or an engine die-out. This condition may be caused by low signal strength from the crank position sensor due to a larger than desired distance to the flywheel sensing ring.
Check to see if the vehicle has a slotted crank position sensor:
If the vehicle has a slotted crank position sensor and new CPS grommet, do not install a new sensor, but reinstall the slotted sensor that was on the vehicle and verify that it is good using procedures in the 1989 Jeep Service Manual 81-370-9045 on page 14-87.
- If the vehicle is equipped with a slotted crank position sensor (see Figure 1), check to see if the CPS grommet on the top of the transmission bell housing has been updated (see Figure 2). If the CPS grommet has not been updated, replace the CPS grommet per the Repair Procedure outlined below.
- If the vehicle does not have a slotted crank position sensor already installed, then proceed with the Repair Procedure.
Crank Position Sensor (slotted)
Crank Position Sensor Grommet
NOTE: THE NEW CPS GROMMET MUST BE REPLACED SO THAT THE MAXIMUM SIGNAL OUTPUT CAN BE OBTAINED FROM THE NEW CRANK POSITION SENSOR.
- Turn the ignition switch to the "OFF" position.
- Disconnect the Crank Position Sensor (CPS) from the engine harness.
- Raise the vehicle using a lift.
- Remove the old CPS and grommet.
- Install the new CPS grommet.
NOTE: MAKE CERTAIN THAT THE CRANK POSITION SENSOR IS COMPLETELY BOTTOMED ON THE MACHINED LIP OF THE BELLHOUSING AND IS AS CLOSE AS POSSIBLE TO THE FLYWHEEL SENSING RING WITHOUT CONTACTING IT.
- Install the new Crank Position Sensor and loosely attach the retaining bolts.
- Firmly press down on the slotted hole side of the CPS until it bottoms on the machined lip of the bellhousing. While holding the CPS down against the bellhousing, tighten the bolt on the slotted side of the CPS to 16 ft.lbs.
- Tighten the remaining attaching bolt to 16 ft.lbs.
- Secure the lead of the CPS to the retaining clip on the bellhousing to prevent its contact with the exhaust manifold.
- Lower the vehicle.
- Connect the CPS to the engine harness.
If this repair has been made, or hasn't fixed the problem, the other TSB is 18-54-89 REVISION A
recommending cleaning of the throttle body assembly, DIY: Cleaning Throttle Bodies
, and replacement of the PCM.
ECU (Automatic Transmission)
ECU (Manual Transmission)
Mopar Choke and Linkage Cleaner