Jeep 4.0 questions

4x4_365

New Member
Joined
Oct 9, 2014
Location
Wake Forest, NC
I have a 1995 Jeep gc 4.0 that is not getting spark. I have replaced the spark plugs, spark plug wires, coil, distributor, tps, cps. it had jumped timing so I also replaced the push rods, timing chain, and the chain guide. I towed it to jeep and they couldn't find the reason. Any help is appreciated!
 
4x4_365 said:
I have a 1995 Jeep gc 4.0 that is not getting spark. I have replaced the spark plugs, spark plug wires, coil, distributor, tps, cps. it had jumped timing so I also replaced the push rods, timing chain, and the chain guide. I towed it to jeep and they couldn't find the reason. Any help is appreciated!
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Where are you located?
 
Wake Forest NC, I took it to the jeep dealer in Raleigh.
 
Does the coil have voltage? Are the injectors firing? Do you have a pickup/cmp waveform? Is the pcm seeing engine speed?
 
Brand new coil is not getting voltage, injectors are firing, idk about cmp, and the pcm is not.
 
The oil gauge also tops out when key is turned to on
 
Not atm, I am about to do a complete wire check hoping its just something unplugged.. I have been told that the computer had to be reset if you replace the distributor, is that BS or the truth?
 
Any links on how to time the distributor, i guess that how to put it.
 
When I recheck the coil where should I check for voltage? I just replaced the battery (like 4 mins ago) and am hoping that is the power issue
 
Check all of the grounds going from battery to engine and engine to body, etc. The oil pressure sounds like a connection issue.
 
I pulled the oil pressure gauge out of the motor and it is burned up, so that is an easy fix. is there anyway to test the pcm? I have been told that is what I need to to check next.
 
If you don't have voltage at the ppm why are you wanting to test the pcm? lol start with a voltmeter with the negative lead to ground, positive lead to the dark green &orange wire at the coil. With key in on or start position you should find 12v. If you've got 12v take a test light to positive to the gray wire, try to start the vehicle and watch for the test light to flash. This will lead you to the fault.
 
Thanks, I will say this is a bigger pain then what I thought at the beginning. :beer:
 
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