Fuel 1994 Gt Fuel Pump Wiring Help Needed

Discussion in '1994 - 1995 Specific Tech' started by Lcfrshadow, Apr 6, 2012.


  1. Lcfrshadow

    Lcfrshadow New Member

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    Since i cant figure out why my fuel pump wont get power, i am now just ready to wire it straight up to the battery with a relay and toggle switch. the thing is, i have heard that by doing so, you lose power to the injectors. how do i go about doing this the right way?
    i have already tried to figure out what is not allowing power to the pump and am just ready to drive my car. plus i would rather have it on a switch anyway.
    help please.
     
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  2. BlownFiveLiter

    BlownFiveLiter have car, will race....wait, it doesn't run

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    Posting in the correct forum might help (it'll be moved shortly, we're in 4.6 Tech). Do you have spark and injector pulsing? A very common issue is the stator inside the distributor goes bad and then you lose both, plus your fuel pump won't run because it gets the signal to run from the stator. It's possible that you have a bad relay inside of the CCRM, too. Unfortunately the CCRM is not a serviceable unit and requires replacement when part of it fails. Have you checked all of your fuses inside the underhood fusebox, and also checked the inertia switch in the trunk?
     
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  3. Lcfrshadow

    Lcfrshadow New Member

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    Just so people know and can understand....
    i.have checked the fuses, the wires, changed fuel pump which doesnt even prime. no fuel pressure in line, checked the inertia switch, chang ed the ccrm which was a ford one that was serviced in 2008. i know it isnt the injectors as the car will run if a fuel source is supplied. so that rules out ignition. its a fuel problem and i need to know how to bypas the technical bull!
    And where do i post if not in this section? there is no 94-95 sn95 5.0 section.
     
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  4. 99FiveOh

    99FiveOh Advanced Member

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    Uh, there is a 94/95 section, your post now resides in it. Sure, you can run your own wiring with relay and toggle switch, but that's a hack and probably won't last long that way, especially when you forget to shut the pump down and it runs all night.

    Technical bull? These cars are about as non-technical as they get! It's a very simple circuit and you just have to back probe until you find power. There will be power somewhere! If you can't figure it out take it to a Ford dealership.
     
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  5. Lcfrshadow

    Lcfrshadow New Member

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    Thanks. the question now is if i wire it up directley with a relay, what do i do with the old wiring? i am pretty sure my injectors wont work because of the broken circuit... or am i wrong?
     
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  6. 99FiveOh

    99FiveOh Advanced Member

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    The computer won't care if the fuel pump is pumping or not and it really has not way to tell if it is. In the computer's way of thinking, engine running = fuel pump pumping. Make sense? When my brother and I swapped a 94/95 drivetrain into his 97 V6 body, we didn't realize the headlight/fuse panel harness was completely wrong, so we had everything working BUT the fuel pump. We simply took a jump box back there and used a couple alligator clips on the fuel pump harness and she fired right up. A completely separate power source was powering the pump and the computer couldn't care less!

    What you need is to reference the fuel pump priming circuit off the computer and use that to signal your relay. I'm not sure if that particular circuit is hot in "run" and "start" thought. The right way to do it is figure out why the factory setup isn't working. It's not rocket science, just go to www.veryuseful.com and check out the wiring diagrams. Then follow the circuits to their sources and see why they aren't getting power.
     
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  7. toyman

    toyman SN Certified Technician

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    Why are you hesitant to trace the wiring back to the source of the problem. As was mentioned the problem is likely in the CCRM which contains the fuel pump relay as well as others.
    Have you tried a temporary power lead to the pump and found that it does work? I don't see where you have back probed from the pump to find where the power lead is broken. Have you checked the FP ground?
     
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  8. Lcfrshadow

    Lcfrshadow New Member

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    I got it running yesterday. turned out to be the inertia switch. Its weird because i checked it like tgree times with a multimeter. To the anyone with the same or similar problem, an easy way to test if your switch is the problem, is to unplug your inertia switch. Take a paper clip and place one side of the clip in the b/y hole of the plug and the other end of the clip goes i nto the b/p hole of the plug. take a wire and attach it to the paper clip ground it. once you turn the ignition key to the on position, you should here your fuel pump prime. hope this helps anyone.
    to all that chimed in, thanks for the help.
     
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  9. Noobz347

    Noobz347 Stangnet Facilities Maint Tech... Er... Janitor Admin Dude

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    :doh:
     
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