1994 jeep XJ Wont start
#17
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Year: 1999
Model: Cherokee
Engine: 4.0
Spark: 12 volts from ignition switch to the ASD relay; when the key is first turned on the PCM provides a ground to the ASD relay to energize it, then the ASD relay passes 12 volts to the coil primary side. If no crank sensor signal is generated after a couple of seconds the PCM cuts the ground to the ASD relay (and fuel pump relay too) and that cuts power to the coil (and fuel pump). Key to START and once again the PCM energizes the ASD relay. Now, a critical element is the crank sensor--no signal from the crank sensor and the PCM won't trigger the coil to provide spark.
If you have no spark, gotta concentrate solely on that at this time. First thing to try is to swap the ASD relay in the power distribution center (black box under the hood) with another relay. These relays are all the same part number so swapping is no issue.
There is no ignition control module (ICM) on a 94; that went away after 1990. A faulty throttle position sensor will not inhibit spark.
Good luck and keep us posted!
If you have no spark, gotta concentrate solely on that at this time. First thing to try is to swap the ASD relay in the power distribution center (black box under the hood) with another relay. These relays are all the same part number so swapping is no issue.
There is no ignition control module (ICM) on a 94; that went away after 1990. A faulty throttle position sensor will not inhibit spark.
Good luck and keep us posted!
Last edited by tjwalker; 01-01-2014 at 06:27 PM.
#20
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Year: 1996
Model: Cherokee
Engine: 4.0
I dont understand what it is..and me being out of the job i dont really want to pay a shop to go through her.. So here is were we are at know.....no power to the coil, i poked the holes with my test light and nothing is there. I recently replaced the CPS but i got it from advanced auto, i did read that it may not work and i should get a mopar aproved part. would it be the O2?
#22
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Year: 1991
Model: Cherokee
Engine: 4.0 HO
Had the same issue awhile back. Did all the something, threw parts at it and still had no spark. So quick question when you turn your key to the on posistion( not start) does you check engine light come on? Can you do the key trick and pull the engine codes? I couldn't do that, my light wasn't comming on and I couldn't pull codes. Checked the check engine lamp to be sure and it was good. Turns out my PCM was bad. Checked all my grounds to make sure they were good then traced the harness to make sure there wasn't any shorts that may have caused it to go bad. I found nothing, tossed in a new PCM and it fixed the issue. Worth as shot.
#24
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Year: 1996
Model: Cherokee
Engine: 4.0
UPDATE!!!
I went to the junkyard and pulled a pcm from a 1995 cherokee along with a o2 sensor for $20. i went and put it in and tryed to turn it over. i am getting some smoke from a ground wire mounted on the drivers side back of the block it runs from the block then to the fire wall and is like a tape wire. im going to hope this is the issue! wish me luck
I went to the junkyard and pulled a pcm from a 1995 cherokee along with a o2 sensor for $20. i went and put it in and tryed to turn it over. i am getting some smoke from a ground wire mounted on the drivers side back of the block it runs from the block then to the fire wall and is like a tape wire. im going to hope this is the issue! wish me luck
#28
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Year: 1996
Model: Cherokee
Engine: 4.0
No its burning off the bolt running into the block. if you read the past posts im having a problem with my jeep not wanting to start. i did see somewhere on here someone said that the wire we are speaking of is a ground wire for the spark plugs or something
#29
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Year: My Jeep is a GMC
Probably a dead short that's killing the battery IMO, would be best to figure it out before it burns. Do you have a lot of rodent chewed wiring? Have you performed a parasitic draw test yet?