Fuel pump relay wires 1970 Buick riviera

Discussion in 'Lost and Found' started by sonofbuick70, Jun 12, 2021.

  1. sonofbuick70

    sonofbuick70 New Member

    Signed up here to help try to find a fuel pump relay wire.. for my dads 1970 Buick riviera. Everything works minus the wire dropped a pin which I’m sure it’s been the source of issues for a while now… any help is appreciated here’s the picture of the wire needed and the two pins on top of the part.
     

    Attached Files:

  2. Nailhead in a 1967

    Nailhead in a 1967 Kell-Mnown Wember

    You know that the fuel pump on the 1969/1970 Riviera is only working when there is enough oil pressure?
    So the engine has to crank/run to activate the fuel pump.
    There is also a fuse for the fuel pump, located on the fire wall in the engine bay.
     
  3. Nailhead in a 1967

    Nailhead in a 1967 Kell-Mnown Wember

    From Yardley's website:

    "I have had the luxury of meeting many Riviera racers.
    Two of them are brothers from the Chicago area.
    And they happen to have very high powered 69 and 70 Rivieras.

    And as a result, they have discovered that the factory electric in-tank fuel pump just can't supply the fuel requirements of high horsepower engines.
    It just doesn't flow enough nor does it have the pressure.
    And as a result (and I've experienced it too) once the engine starts revving in the higher RPM range the fuel bowls on the carburetor empty
    and the car literally runs out of gas and falls flat on its face - some refer to it as "nosing over".

    But...

    They have learned that the fuel pump from an 85 - 88 Ford truck with a 4 cyl or 6 cyl engine
    (I'm guessing it is for a Ford Ranger) is a direct bolt in replacement.
    The AC Delco number is EP297.

    I just told the NAPA guy I wanted that number and he just went and got it - and it was he that told me what it originally fit.
    Pressure at idle went up from 5psi to 6 3/4 to 7 psi and from 1.5 psi at WOT to around 4 psi at WOT, and the flow went from 30 gph to 40 gph. Needless to say there was much improvement, and no bogging at high RPM.

    Here you can see the 2 pumps side-by-side (click on the pic to enlarge it).
    While they are a direct bolt in, there are a couple of slight differences.

    You'll also notice in the picture on the right that I have used hose clamps to hold the OEM replacement pump in place, and I have done so with the new Ford pump as well.
    I don't like risking having things separate when there is an easy work around.

    [​IMG] [​IMG]



    The new pump is slightly shorter in body, inlet neck and exit neck lengths.
    Even so, I was able to just fit it in where the old one was.

    I believe it sits a little higher in the tank, so be sure to not let the fuel get too low.
    I tried like heck to affix the old sock, but it just wouldn't clamp down tight enough and I feared it would come off and lodge
    somewhere that I didn't want, so I used the sock it came with.

    The guys in Chicago installed it with no sock (I think to increase the flow a bit - and about 2 months later their pump failed!)
    but I chose to keep the debris out of the pump and maybe lose a tad of flow.

    And I also wasn't happy with how inflexible the new sock is, and didn't want to run the risk of it interferring with my fuel gauge float,
    so I installed it with the short end pointing down.

    I also had to do a little trimming to the rubber sleeve around the pump as it was bumping the float arm.
    I have not installed a fuel pressure regulator as of yet, and I'll decide after driving it a while if it needs one - but I don't think it will.

    That's it!
    You don't need to plumb a return line, and it sounds just like the OEM Buick pump.
    And now you have a much better fuel pump."

    Click here to visit Yardley's website 1BadRiv

     
  4. sonofbuick70

    sonofbuick70 New Member

    do you have a picture so i can refer to it? i apologize im not familiar with this car,
    he got an oil change and his car has since this post has not started.
    i can't help my pops the way id like to. im just not versed in buick enough.
    its hard enough this car has brought me nothing but stress HAHA.
    but please any knowledge on this matter helps. ive tried everything.
    and i can't find the fuse for the pump in the engine bay.its probably right under my nose too.
    also, the oil light goes on when we rigged and bypassed a wire to the pump.
     
  5. Nailhead in a 1967

    Nailhead in a 1967 Kell-Mnown Wember

    I don't have a photo of the fuse location, but is there power at the wire you showed in the first post when you turn the ignition on?
    Did the fuel pump run when you bypassed the wiring?

    The oil light came on, so you didn't put 12 volts directly to the disconnected fuel pump?

    So the trouble started right after an oil change?
    It almost sounds like you have no oil pressure and may have to pack the oil pump with vaseline to build up pressure again...

    After you crank the engine, can you see any oil on top of the cylinder head, looking through the oil filler opening in the valve cover?
    Maybe you have to remove the driver's side valve cover to have a better look at this when you crank the engine.

    Electric scheme from the 1970 Buick Chassis Service Manual:

    Fuel pump 70.jpg

    70 FP.jpg
     
    Last edited: Jul 3, 2021
  6. Nailhead in a 1967

    Nailhead in a 1967 Kell-Mnown Wember

  7. Nailhead in a 1967

    Nailhead in a 1967 Kell-Mnown Wember

    There's a fuel pump fuse in the fuse block under the dash, from my 1970 Riviera Owner's Manual:

    70 fuse block.jpg

    But that fuse should be okay since the oil pressure light came on when you applied power to the fuel pump wiring.
     

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