Fuel Pump - Electric — GMC Pickup R1500 (1987-1987)

Fuel Pump - Electric GMC Pickup R1500

FUEL PUMP FLOW TEST

Relieve fuel system pressure by removing "FUEL PUMP" fuse from fuse block. Crank engine. Engine will start and run until residual fuel in lines is used. After engine stops, crank engine an additional 3 seconds to relieve any remaining pressure. Turn ignition off and install fuel pump fuse.
Connect a fuel hose to throttle body feed line. Route line to a one quart, calibrated container. Apply battery voltage to terminal "G" of Assembly Line Communications Link (ALCL). (Scheme 37) Fuel pump should supply 1/2 pint (240 ml) or more of fuel in 15 seconds.
If fuel supply is within specifications, pump is operating properly. If fuel supply is less than specifications, check for restrictions in supply line. Repair or replace line if necessary. If there are no restrictions, perform «FUEL PUMP PRESSURE TEST»(/gmc/pickup-r1500/1987-1987/remont/testing-diagnostics/#fuel-pump-electric__fuel-pump-pressure-test).

Scheme 37: Assembly Line Communications Link Test link is under left side of instrument panel. Courtesy of General Motors Corp.

Relieve fuel system pressure by removing "FUEL PUMP" fuse from fuse block. Crank engine. Engine will start and run until residual fuel in lines is used. After engine stops, crank engine an additional 3 seconds to relieve any remaining pressure. Turn ignition off and install fuel pump fuse.
Remove air cleaner. Plug thermal vacuum port on throttle body. Install Fuel Pressure Gauge (J-29548-A) between throttle body and fuel filter. Start vehicle, and note pressure reading. Pressure should be 9-13 psi (.63-.91 kg/cm 2 ).
If pressure exceeds specifications, Inspect throttle body injection system. Relieve fuel pressure. Remove gauge and connect fuel line. Start engine and check for leaks. Install air cleaner. Remove plug from thermal vacuum port on throttle body.

Remove "FUEL PUMP" fuse from fuse block. Crank engine. Engine will start and run until residual fuel in lines is used. After engine stops, crank engine an additional 3 seconds to relieve any remaining pressure. Turn ignition off and install fuel pump fuse.
Disconnect battery negative cable. Raise and support vehicle. Remove fuel tank. Turn sending unit lock ring counterclockwise. Pull lock ring away from tank. Remove fuel pump/sending unit assembly from tank. Remove pump from sending unit. To install, reverse removal procedure using NEW O-ring seal.. Start engine and check for leaks.

Note. Specifications table not available. Refer to specifications within appropriate COMPONENT TESTING subject(s) in this article.