When troubleshooting a Fuel Pump that is not working, the first step is to verify that the vehicle has power. A malfunctioning fuel pump is often caused by a lack of power, so it is important to check the fuse and relay that control the fuel pump. In many cases, a simple blown fuse can cause the pump to stop working. It generally costs between 1 to 5 dollars and can be located in the car’s fuse box, usually under the dash or near the engine.
The next step involves testing the electrical system of the fuel pump. Using a multimeter, the voltage at the fuel pump connector is measured. The voltage must fall within a certain range, usually 12-14 volts, for the fuel pump to work. If it were lower than the above-stated range, that voltage could mean problems with your vehicle’s wiring, fuse, or even relay issues. Indeed, over 30% of fuel pump failures are said to be electrical-that is, due to wiring or relay problems-as stated by several experts of the Automotive Service Association.
Another very important diagnostic tool is the fuel pressure gauge. Most vehicles require a fuel pressure range of about 40-60 psi to run well. If it is considerably lower or if there is no pressure at all, the problem could be with the Fuel Pump itself. This test should be done by connecting the fuel pressure gauge to the fuel line and checking for adequate fuel pressure when the ignition is turned on.
These telltale signs include issues with starting up the engine or stalling after operating for some time. Sometimes, a malfunctioning fuel pump can result in some sputter or hesitating of the engine during accelerations due to the small size of the volume of the Fuel Pump, an indication that there is a shortage supply of fuel in the engines. According to the Car Care Council, fuel systems failure, where fuel pumps are also inclusive, leads to almost 10% breakdown.
If the fuel pump passes these tests and still shows signs of failure, further inspection may be necessary. Some vehicles may have a diagnostic code that can be accessed with an OBD-II scanner to identify fuel system-related problems. A faulty Fuel Pump could also be caused by clogged fuel filters, contamination in the fuel tank, or damage to the pump itself, which may require professional assistance for repair or replacement.