How to Check for Fuel Delivery in a Mitsubishi Galantby ContributorUpdated November 07, 2017
How to Check for Fuel Delivery in a Mitsubishi Galant. The Mitsubishi Galant was manufactured by Mitsubishi Motors as a compact from 1969 to 1998 and then as a midsized four-door sedan from 1998 on. The Galant was named Import Car of the Year by Motor Trend Magazine in 1989. Check for fuel delivery problems in a Mitsubishi Galant if the engine starts running rough, stalls out in traffic or won't start at all.
Relieve fuel system pressure in four-wheel drive Galant models by loosening the gas cap and undoing the harness connector to the fuel pump. Raise the Mitsubishi Galant if necessary. In all-wheel drive Galant models, disengage the wiring that connects the fuel tank and the fuel pump cover. Start the vehicle and let the engine run until it stalls. Turn the ignition off and disconnect the negative battery cable.
Disconnect the fuel pressure sensor vacuum hose. Check for fuel in the line. If there is fuel present in the line, the fuel delivery problem is likely due to a faulty fuel pump pressure regulator. If there is no fuel in the line, reattach the vacuum hose and continue with the fuel delivery diagnostic.
Twist off the fuel pressure test port cap and attach a pressure gauge to the fuel pressure valve. Reconnect the negative battery cable, start the engine and let it idle. Check the gauge. It needs to register approximately 27 psi. Disconnect the vacuum hose and check the gauge again. It needs to read between 36 and 38 psi. Pressure that's too high indicates a malfunctioning pressure regulator. A low pressure indicates a broken fuel pump that needs to be replaced.
Cut the engine, relieve system pressure again and remove the negative battery cable.
Remove the fuel filter. Undo the retaining cap on the fuel pump with tool MB991480. Disconnect all wiring and hoses to the fuel pump, which is accessible by lifting the back seat. Remove the fuel pump and filter.
Examine the filter for clogs and replace if necessary. If there are no clogs, the fuel delivery problem is probably caused by a breakdown in the fuel pump itself.