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no injector pulse

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Old Nov 15, 2013 | 08:15 PM
  #1  
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From: Gardnerville Nv.
Year: 1988
Model: Cherokee
Engine: 4.0
Default no injector pulse

Alright i brought home an 88 larado last night no pulse no power at all to the injectors iv replaced the cps the ignition switch iv reniewed the c101changed the ecu i have fuel pressure new pump new filter im at a loss and need it running asap as my winter jeep currently has no axle.
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Old Nov 15, 2013 | 10:15 PM
  #2  
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From: Prescott, Az
Year: 1990
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Have you tested the CPS output even though it's new?

Did you "tweak" the connectors in the C101?
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Old Nov 16, 2013 | 12:20 AM
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From: Gardnerville Nv.
Year: 1988
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Engine: 4.0
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i have no way to test it but i have several new in box and iv tried two of them, could that cause my injectors to not pulse? how can i test it without a dvom?
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Old Nov 16, 2013 | 09:24 AM
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From: Prescott, Az
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Go here and get this.

http://www.harborfreight.com/7-funct...ter-98025.html

When you get home, read this:

http://learn.adafruit.com/multimeters/
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Old Nov 16, 2013 | 10:09 AM
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Injectors have continious voltage but will not open untill the PCM completes the ground path.

Check the PCM ground and associated ground wires before throwing more money at your rig.

Also try swapping the ASD relay with a known good relay in your PCM.

Checked/cleaned your NSS yet?
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Old Nov 16, 2013 | 12:19 PM
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From: Gardnerville Nv.
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i havent checked any of those yet where are they located and what signs should i look for
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Old Nov 16, 2013 | 12:39 PM
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Black wires screwed to the body next to the PCM.
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Old Nov 16, 2013 | 01:12 PM
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i can not find my PCM anywhere
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Old Nov 16, 2013 | 01:28 PM
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D'oh!!!

You've got a 88....no PCM.
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Old Nov 16, 2013 | 01:31 PM
  #10  
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From: Gardnerville Nv.
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alright so where do i go from here then? i was told there are four grounds from my block to the frame but i only have three grounds. could that do it? it was running just fine then the fuel pump stopped getting power i ran a switch to it and about a week later the injectors just stopped
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Old Nov 16, 2013 | 01:34 PM
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Originally Posted by SeriousOffroad
D'oh!!!

You've got a 88....no PCM.
LOL. And the Renix grounds all the injectors and gives them POWER to fire them.
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Old Nov 16, 2013 | 01:44 PM
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From: Prescott, Az
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Originally Posted by Redneck_jeep
alright so where do i go from here then? i was told there are four grounds from my block to the frame but i only have three grounds. could that do it? it was running just fine then the fuel pump stopped getting power i ran a switch to it and about a week later the injectors just stopped
Post #1 in my link below.
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Old Nov 16, 2013 | 02:06 PM
  #13  
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From: Gardnerville Nv.
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Originally Posted by cruiser54
Post #1 in my link below.
Thanks cruiser but iv already tried i use all your tips as soon as i pick up a jeep as it usually solves all problems.

UPDATE: i pulled down the steering coloum as its broken at the tilt the ignition switch was fried so i replaced now the jeep wont even try to turn over however still getting power to everything but my injectors.
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Old Nov 16, 2013 | 02:24 PM
  #14  
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From: Prescott, Az
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That switch is adjustable on the column by sliding it up or down.
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Old Nov 16, 2013 | 03:29 PM
  #15  
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From: Gardnerville Nv.
Year: 1988
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sliding the switch didnt make a diffrence i even pulled it back out and tried using a screw driver still nothing im at such a loss with this jeep.
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