1993 wrangler starting problems

hi, I use to have the same problem I had to change engine electrical wires, then I had to change the crank sensor and the module ( destributer ) first let him check the complete wires installation then if they are good let him change the crank sensor

before going crazy , check the crank sensor out, a bad crank sensor will cause timing to be out of sync. more then likely engine will not start. or irregular rpm function if vehicle starts at all. it controls timing and sends info to pcm. if a crank sensor fails while driving the engine will die out. have scanned if check engine light is on. CPS symtoms are: car dies and won't re-start till it cools down, or won't start at all.
first of all, if crank sensor is ok, then you can check the timing belt.

Jeep Cherokee Limited Crank, No Start
Q. 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...
Pawel
A. This was a widespread problem for Chrysler and they issued a couple of TSBs to address the problem. The first was:
Models:
1989 MJ & XJ Bodies
Subject:
4.0L No-Start, Hard Restart, or Engine Die-Out. Vehicles Equipped With Automatic Transmission Only.
Index:
DRIVEABILITY
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)
SYMPTOM/CONDITION:
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.
DIAGNOSIS:
Check to see if the vehicle has a slotted crank position sensor:

1. 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 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.

1. If the vehicle does not have a slotted crank position sensor already installed, then proceed with the Repair Procedure.

PARTS REQUIRED:
1 Crank Position Sensor (slotted) P/N 83100067 1 Crank Position Sensor Grommet P/N 83100068 REPAIR PROCEDURE:

1. Turn the ignition switch to the "OFF" position.
2. Disconnect the Crank Position Sensor (CPS) from the engine harness.
3. Raise the vehicle using a lift.
4. Remove the old CPS and grommet.
5. Install the new CPS grommet.

NOTE: THE NEW CPS GROMMET MUST BE REPLACED SO THAT THE MAXIMUM SIGNAL OUTPUT CAN BE OBTAINED FROM THE NEW CRANK POSITION SENSOR.

1. Install the new Crank Position Sensor and loosely attach the retaining bolts.
2. 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.
3. Tighten the remaining attaching bolt to 16 ft.lbs.

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.

1. Secure the lead of the CPS to the retaining clip on the bellhousing to prevent its contact with the exhaust manifold.
2. Lower the vehicle.
3. 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.
PARTS REQUIRED:
1 ECU (Automatic Transmission) P/N 53007842 1 ECU (Manual Transmission) P/N 53007843 1 Mopar Choke and Linkage Cleaner P/N 4549619

Ok...you mentioned that there is no spark coming from the coil when it's in no start...Is there power from the alternator going to the coil?
One other item...If the timing chain is worn and stretched, it is possible that the cam sensor and crank sensor are out of phase with each other, just enough where a temperature difference will change starting ability.
One question...while in no start, have you tried changing the throttle position while cranking to see if it lights at part or 3/4 throttle?

yes the crank sensor is probebly your problem.

If extremely dirty, filter could restrict air flow and eventually produce a no start or low power condition. cps generally gives a shutdown for no obvious reason and no spark when starting.(sometimes re starting after cool down)

it sounds like you may have a bad crank positioning scensor or could possibly be in the ecm try the wires first then i would go from there

Crank position sensor has a higher failure rate than it should...however i would not change it "at random" Check for continuity between b&c terminals of the sensor with a digital ohmeter.
There should be no continuity between them (b&c should be marked on connector) No continuity reading is same as when probes are not connected to each other.
I really dislike when people try and help and use terms that owners can't understand ... "check your zxy and qtr then add an abc" dosen't seem helpful. I hope I am as clear as I can be!!!
Good luck.

let me know if it works out

Hi krh60, I would strongly recommend having the cps (cam positioning sensor) and the css (crank shaft sensor) checked immediately, both can cause your problem and both throw no codes when running, in early stages the vehicle may start again or it may not. Ford also has a cps problem on their 7.3's also see if Chrysler has a recall on these parts you may get lucky hope this helps good luck to you.