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number 5 injector not pulsing

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Old 05-14-2016, 08:40 PM
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Default number 5 injector not pulsing

Just bought my second XJ. Number 5 injector is not getting a pulse from the ECM. Anybody know what pin on the ECM plug goes to #5 injector?
Old 05-14-2016, 11:20 PM
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Originally Posted by htrotte
Just bought my second XJ. Number 5 injector is not getting a pulse from the ECM. Anybody know what pin on the ECM plug goes to #5 injector?
Thanks for your post.

We’re here to help, but you must understand that all Jeeps are not the same.
In order for us to give you more accurate advice and help, we must know the following, as applicable, along with detailed information as to the symptoms/problems etc:

Year
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Transmission
Transfer case
Old 05-15-2016, 12:16 PM
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Sorry about that. It's a 1995 Cherokee Sport. Factory stock. Auto trans, 4.0 liter engine. it is a 4x4 but i have not crawled under to see which transfer case and axles it has.
Number 5 cylinder is dead. I have installed new rotor, cap, wires and plugs. It is definitely getting spark. #5 injector is not getting a pulse to to open it like the rest are getting. I was trying to find out what pin on the ECm this injector goes to so i can do a continuity check on the wire before I start hunting an ECM. I have also verified compression in all engine cylinders.

Any help I can get will be gratefully accepted.
Old 05-15-2016, 12:17 PM
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.
Old 05-15-2016, 12:29 PM
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Default 95 Fuel Injection Diagram

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Old 05-15-2016, 01:29 PM
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Originally Posted by CCKen
Old 05-15-2016, 08:43 PM
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Thanks guys! Got good continuity from ECM to injector. Guess I need to start looking for an ECM. Any idea which ones are interchangeable?
Old 05-16-2016, 06:13 AM
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'95 PCM, 4.0, auto trans, part number is 56027698. No interchangeable PCM's. This part number should be on a decal on the side of your PCM.


Sometimes when an injector impedance is very low it will smoke the PCM driver for that injector.


Check the resistance of #5 injector (pin-to-pin) to see if it's way below around 13 Ohms. Normal resistance is 14.5 +/- 1.2 Ohms at 68*F.

Last edited by CCKen; 05-16-2016 at 06:16 AM.
Old 05-21-2016, 07:11 PM
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Part number on the PCM in my XJ is 56026948.

That what I need to look for?
Old 05-21-2016, 09:09 PM
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Originally Posted by htrotte
Part number on the PCM in my XJ is 56026948.

That what I need to look for?
Google that number. It's for a 94 to 95 Grand Cherokee.
Old 05-22-2016, 07:55 AM
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Originally Posted by htrotte
Part number on the PCM in my XJ is 56026948.

That what I need to look for?

See post #8 for PCM part number.


Did you read the resistance of the injector?
Old 05-22-2016, 01:03 PM
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Resistance of all injectors is within range specified.

These PCM's confuse me. the pcm in my jeep now ends in 948. is that the wrong one?

Whatever happened to the good old points and condenser ignition!!!? LOL
Old 05-22-2016, 01:54 PM
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Originally Posted by htrotte
Part number on the PCM in my XJ is 56026948.

That what I need to look for?
'95 PCM, 4.0, auto trans, Federal Emissions and California Emissions, part number is 5602 7698,
Old 05-28-2016, 09:59 PM
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Found a 56026948 on ebay for $50 bucks so thought i would take a chance. It worked! Purrs like a kitten now. Now to get my door put back on. Dang hinge broke away from the body
Old 05-29-2016, 07:55 AM
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Originally Posted by htrotte
Found a 56026948 on ebay for $50 bucks so thought i would take a chance. It worked! Purrs like a kitten now. Now to get my door put back on. Dang hinge broke away from the body
Great.

#5 injector driver must have been bad.
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