Fuel pressure regulator?

Discussion in '94-95 5.0 - Specific' started by red9535, Jul 23, 2007.

  1. red9535

    red9535 Member

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    I currently have my fuel pump (holley blue) pumping all the time when the car is on.. no fuel pressure regulator. What are the downsides to this? Should I invest in a fuel pressure regulator? Any recommendations.. would the OEM ford one work?
     
  2. ryclef331

    ryclef331 Well-Known Member

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    No a factory EFI regulator will not work. It mounts to the rail and is designed to operate at a higher pressure. YES, you should run a regulator on the car though. Usually when the holley blue is sold with a regulator....any carb'd regulator would be fine.
     
  3. red9535

    red9535 Member

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    I'm not disagreeing- but I am uninformed on the subject. What is the purpose of a fuel pressure regulator, and why is it necessary? Any suggestionsas to which one to get? (I actually have Holley Red - I was mistaken (it came with the car i bought)

    I mean, obviously, I realize what it does.. it regulates the fuel pressure.. but, why is this necessary? Right now it's run like this:

    Tank > Pump > Fuel filter > Carburetor

    And you guys are saying it should be run like this:

    Tank > Pump > Fuel Filter > FPR > Carburetor

    ?

    Please elaborate!
     
  4. ryclef331

    ryclef331 Well-Known Member

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    If you just let the pump go unregulated, you'll run TOO MUCH fuel pressure and the car will CONSTANTLY run rich. You NEED to have a regulator. its goes

    Tank-pump-filter-regulator-motor.

    The regulator has an orifice that opens and closes to restrict/regulate how much pressure the motor will see. on a carb'd car you need about 8-9lbs of pressure at idle. If you're seeing 19lbs unregulated, you'll never get the carb tuned....
     
  5. red9535

    red9535 Member

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    So do I just buy a regulator and hook it up, or do I have to tune it, too?
     
  6. ryclef331

    ryclef331 Well-Known Member

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    slap it on there (with a gauge of some sort of course) and set it to whatever the reccomended starting pressure for your car is....probably between 7-9lbs. Tune from there.
     
  7. red9535

    red9535 Member

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    So set the FPR for 7-9 lbs, then leave that alone, and tune my carburator from there? It's etiher that, or leave it the way it is (don't worry, i'm not going to) and tune the carburator for all that fuel it's spitting?
     
  8. ranger50toy

    ranger50toy New Member

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    Too much fuel pressure pushes the float valve open and floods gas out the vents. You will be running rich no mater what you try to adjust without the regulator.
     
  9. mystang94

    mystang94 New Member

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    i always ran filter-pump-filter regulator-carb. but to each his own. but yes u need a regulator too much fuel otherwise. must have been a bitch trying to set the floats on that thing. too much fuel can wash down ur cylinders as well.
     
  10. red9535

    red9535 Member

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    Alright, I got one. It's a Mallory 4309. It has 4 different places to attach hoses on it - how do I hook this thing up?

    There's one on the bottom labeled BYPASS.. then there's 1 on the back, which comes from the fuel pump presumabely.. then there's 2, 1 on top of the other, g oing out towards where the carb would be.

    How do I set this up?
     
  11. ryclef331

    ryclef331 Well-Known Member

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    Read this...its the instructions. There is a diagram on pg 1.

    The bottom port is the return back to the tank. The ports around the sides...they're both fuel pressure from the pump AND to the carb. Plug any unused ones. SO you should have a line running from the pump to anyone of the ports around the side then a line from any of the ports on the side to the carb. Use one of the ports to install a fuel pressure gauge. You can get one at the parts store for dirt practically. Hook up the vaccum reference line to any vaccum source.

    http://go.mrgasket.com/pdf/4309.pdf