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Thread: External electric fuel pumps in series with in-tank electric fuel pumps.

  1. #1

    Default External electric fuel pumps in series with in-tank electric fuel pumps.

    I have a '95 F250 that I will be swapping out the EFI 351W, and putting in a 460 (bored & stroked to 504").
    The 460 will have a Weiand Tunnel Ram with dual 750 4150s.
    The truck has two fuel tanks each with an internal electric fuel pump.
    Should I remove these in-tank pumps, or leave them in?
    Will they work in conjunction with external fuel pumps? Or will this create problems?
    I would appreciate all comments and questions. Thanks, 2UWrangler

  2. #2
    Join Date
    Dec 2009


    I would use the existing EFI fuel pumps. Do not combine the in-tank & external fuel pumps.
    EFI fuel pumps have a wide range of psi capability; you set the exact pressure you need/want.
    Electric fuel pumps only produce volume, the fuel pressure regulator sets the desired pressure.
    Listen to Doug Flynn @ :59 seconds explain how to use EFI fuel pump on a carbureted application: (Holley Fuel Pumps YouTube Video)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, R134a 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, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 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 M/T Street Comp tires.

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