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Thread: Pressure Falling

  1. #1

    Default Pressure Falling

    I'm running a Holley Blue pump with the regulator that came with it (803). Is one side a bypass and the other the carb supply? I have it plumbed with each side of the regulator going to each fuel bowl inlet. The problem I'm having it after running for 5 minutes, one side steadily drops in pressure until it eventually hits 0 psi. Never had this problem before with my last Blue pump & regulator setup.

  2. #2
    Join Date
    Nov 2013
    Chicago IL


    This sounds like what happens when you get vapor lock.
    You may need to run a bleed line that goes from the fuel bowl back to the tank.
    Typically a small line (like a -3AN nitrous line) with a .020"-.040" jet in it will be plenty.
    There are also several bleed kits available on the market, that you can add to just about any carburetor.
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  3. #3


    I've never run into a vapor lock with an electric fuel pump. So you are suggesting a return line? You say from the bowl, do you mean the regulator?

  4. #4
    Join Date
    Dec 2009


    He is actually referring to a bleed line (research it). However, I prefer a return style fuel pressure regulator.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

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