Electrical Fuel Pump Wiring

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by taz8000, Jan 6, 2001.

  1. taz8000

    taz8000 Guest

    Can anyone help me with a wiring diagram for the electrical fuel pump on a '87 Blazer with 305 engine and TBI.
    Here in Belgium we can run cars on natural gas and normal gas. My truck is not running on normal gas. I expect the fuel pump to be faulty (can't hear it run) I would like to check the wiring, but in the Haynes manual I own the fuel pump is left out.
  2. Storm Trooper

    Storm Trooper 1/2 ton status GMOTM Winner

    Nov 24, 2000
    Likes Received:
    Dillon Colorado, Hang'in in the mountains. Renting
    Taz8000, on an 87 Blazer like mine, the fuel pump relay is on the firewall directly above the motor. The spare lead hanging out is to by-pass the relay to prime the pump. With a meter you should be able to test the fuel pump here. The wiring also goes to a oil sending unit on the drivers side of the motor so that if the relay fails, cranking the motor to about 5lbs. of oil pressure will also activate the fuel pump. At the relay you shold have a hot(+) in, fuel pump out, ground(-) and I belive the lead from the oil sending unit and or computer. Good luck!

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