Genuine 1991 Chevrolet Metro Fuel Pump

1991 Chevrolet Metro Parts Questions & Experts Answers

• Q: How to check fuel pump and fuel system pressure to ensure the fuel system is functioning properly on 1991 Chevrolet Metro?

  A: The following checks assume the fuel filter is in good condition; if there are doubts about its condition, install a new one. First, ensure there is adequate fuel in the tank; if the gauge reading is questionable, use a long wooden dowel as a dipstick. For carbureted models, if insufficient fuel delivery is suspected, inspect all fuel lines for leaks. If no leaks are found, check the fuel pump for leaks and functionality by removing the air cleaner housing. Hook up a remote starter switch or enlist an assistant, trace the fuel outlet hose from the pump to the carburetor, and detach it. Connect the cable to the negative battery terminal, detach the ignition coil wires, and place a metal container under the fuel pump outlet hose. Crank the engine for a few seconds; if fuel is emitted in well-defined spurts, the pump is functioning properly, but if it dribbles or trickles, the pump is defective and should be replaced. For fuel-injected models, set the parking brake and have an assistant turn the ignition to the On position while listening for a whirring sound from the fuel pump, which should last a couple of seconds and continue while the engine runs. If there is no sound, the fuel pump or main relay circuit may be defective. Relieve the fuel pressure, remove the air cleaner assembly, and attach a fuel pressure gauge between the fuel feed line and the throttle body. Start the engine and measure the fuel pressure while idling, then shut off the engine and measure again with the key in the On position. If the pressure is not within specification, check for a pinched or clogged return hose or pipe, and inspect the fuel filter for clogs. If all components check out, verify the fuel pump is operational by listening for a brief whirring noise when the ignition is turned to ON and a constant sound when the engine is running. If the pump does not activate, remove the rear seat, detach the black and red wire connector, and check for voltage with a voltmeter. If voltage is present, replace the fuel pump; if not, check the main relay.