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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 creates 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.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

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