A fuel pump check valve is a component of a mechanical fuel pump, which is found on many vehicles that were manufactured before electronic injection. A mechanical fuel pump has a two-port check valve, one that is located on the pump’s inlet and one that is located on the pump’s outlet. The check valve is designed to make the fuel in the vehicle only flow in the correct direction from the fuel pump and to maintain pressure. If a fuel pump’s check valve goes bad, it could cause one or more symptoms.
When the fuel pump’s check valve goes bad, it will not be able to maintain the proper amount of pressure, causing the vehicle to run poorly or stall. A fuel pressure gauge can be used to test the amount of fuel pressure when the vehicle is running. If the amount of pressure is lower than the specifications for your car, the check valve may need to be replaced.