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Thread: Fuel pump

  1. #1
    Member 9t3lightning's Avatar
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    Default Fuel pump

    My 90 wagon has been sitting for 1.5 years went to start it and no fuel pump
    Hum when the key turned on.
    Swapped out the fuel pump relay and still nothing. So changed the pump
    And still nothing. Is there a fuse or fusible link Iím missing ?


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  2. #2
    Still Wrenchin'! friskyfrankie's Avatar
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    Should be a fuse and also a fuel pump protection module (normally in a trunk but somewhere in the back of a wagon). Wagon "buffs" here can post where exactly it can be found. It cuts off the fuel pump in case of a rear end crash.
    What I Own: 1993 Mercury Grand Marquis GS
    What I Help Maintain: 1996 CV / 1988 CV / 1988 Tempo

  3. #3

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    Inside the drivers side panel near the tail lights.
    90 Colony Park LS with GT 40 heads and intake. HO cam, 65 MM TB, 67 MM EGR spacer. Has a 75 MM Pro Flow mass air sensor. Borla XS mufflers. 3L55. Shift kit, 2000 stall Tq convertor...Bilstein shocks, front and rear sway bars.
    90 Colony Park LS 64,000 miles all original. 3L55 tow package....front and rear sway bars.
    91 Grand Marquis GS....HO motor..Bilstein shocks poly bushings and police swaybars. This one handles the best.
    70 Torino Squire with M code 351 Cleveland 3.00 has Magnaflow mufflers. Hidden headlights and power windows. All original

  4. #4
    Beater gonna beat sly's Avatar
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    Default

    The inertia switch (cuts out the fuel pump in case of a collision) in wagons is usually in the dead space behind the rear glove box. If resetting it doesn't help, try jumping the connector to bypass it. They can go bad.

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  5. #5
    Still Wrenchin'! friskyfrankie's Avatar
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    Yep - Inertia Switch - the name did escape me!
    What I Own: 1993 Mercury Grand Marquis GS
    What I Help Maintain: 1996 CV / 1988 CV / 1988 Tempo

  6. #6
    Member 9t3lightning's Avatar
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    Default

    I tried the inertia switch too,
    Iíll try jumping it out and see.
    But as for a fuse? None mentioned in the owners manual or electrical manual?


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  7. #7
    Lost and driftin' Arquemann's Avatar
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    Default

    Quote Originally Posted by 9t3lightning View Post
    I tried the inertia switch too,
    I’ll try jumping it out and see.
    But as for a fuse? None mentioned in the owners manual or electrical manual?


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    Not sure if SEFI is the same as CFI, but my car has a fusible link where the fuel pump relay gets constant power from the starter relay stud.
    1985 Mercury Grand Marquis LS, "Maisa"
    1995 Chevrolet Caprice Classic STW, "Sally"

  8. #8
    GMN Regular WagonMan's Avatar
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    Check for power at the fuel pump relay, its always hot without the key on. WagonMan
    89 Colony Park
    90 Colony Park
    70 HEMI Daytona Convertible

  9. #9
    Member 9t3lightning's Avatar
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    Default

    Ok
    So i can hear the pump coming on now
    Aftermarket pump isnít as noisy as the factory one . But
    Still no start.
    Question on the pump
    Connections, could I have put the wires on backwards and the pump not pumping correctly ?
    I checked the shrader valve and it seeM to have some pressure .


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  10. #10
    GMN Regular DerekTheGreat's Avatar
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    Default

    What is "some pressure?" Perhaps you've got an ignition issue.
    1985 LTD Crown Victoria - SOLD
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  11. #11
    Fastest Boxes In South Jersey 86VickyLX's Avatar
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    Default

    Quote Originally Posted by 9t3lightning View Post
    Ok
    So i can hear the pump coming on now
    Aftermarket pump isn’t as noisy as the factory one . But
    Still no start.
    Question on the pump
    Connections, could I have put the wires on backwards and the pump not pumping correctly ?
    I checked the shrader valve and it seeM to have some pressure .


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    You absolutely could wire it backwards. It won't pump fuel up to the rail. Do you have a fuel pressure gauge?

    How old is the fuel filter?

  12. #12
    Member 9t3lightning's Avatar
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    I do have a pressure gauge will have to try that tomm
    The pump wasnít marked so it was a 50/50 chance
    And itís definitely a fuel issue since she fires right up on starting fluid


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  13. #13
    Member TheEnglishChap's Avatar
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    Default

    I had a fuel issue too, so replaced the following in order:
    1. Fuel filter (under pax rear well);
    2. Fuel regulator (a total arse to get to!);
    3. Fuel pump.
    The pump was actually okay, turned out that little hose from the pump to the rail that had split in a few places.

  14. #14
    Member 9t3lightning's Avatar
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    Default

    Ok so changed the filter just
    To make sure and have 38 for fuel pressure at the schrader valve.
    And all she does is crank
    But if I squirt starting fluid in the throttle body she fires right up
    Wtf


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  15. #15
    Still Wrenchin'! friskyfrankie's Avatar
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    Sounds like the fuel injectors may not be opening. Don't believe a '90 Wagon has a crankshaft or camshaft sensor so the injectors may not be getting power from the PCM. I would check for power at the injector connectors and take it from there. I'm sure someone will correct me if I am way off base.
    What I Own: 1993 Mercury Grand Marquis GS
    What I Help Maintain: 1996 CV / 1988 CV / 1988 Tempo

  16. #16
    Member 9t3lightning's Avatar
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    Took a test light to the injectors
    They have power with the key on
    Like they should


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  17. #17
    Still Wrenchin'! friskyfrankie's Avatar
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    Quote Originally Posted by 9t3lightning View Post
    Took a test light to the injectors
    They have power with the key on
    Like they should


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    Likely so. Forgot, if spraying starter fluid got the car started, the injectors would need to be working.
    What I Own: 1993 Mercury Grand Marquis GS
    What I Help Maintain: 1996 CV / 1988 CV / 1988 Tempo

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