The complete fuel pump assembly might include a fuel gauge sending unit, a pressure regulator valve, a fuel tank pressure sensor, a pump intake strainer and/or the main fuel system filter, and of course the electric fuel pump. We’ll focus only on port fuel injection systems that use the electric pump to generate all the pressure in the system, but most of this information can also apply to the fuel delivery system of direct-injection engines, too. To help you avoid misdiagnosis and comebacks, we’re going to review the components of a fuel pump assembly, describe some diagnostic techniques, and discuss how to give replacement fuel pumps a good chance at a long service life. If enough contamination gets past the pump’s intake strainer, it can actually jam the pump and stop the engine immediately.ĭiagnosing fuel pressure problems is often tricky because the problem can be something other than the fuel pump. The second most common cause is fuel contamination, usually dirt and rust particles that clog the fuel strainer and prevent the pump from drawing enough fuel under high engine load.

The most common cause of fuel pump failure is frequently running the tank low on fuel, which causes the motor to overheat.

Here are the basics for what it takes to diagnose a problem and perform a profitable repair. When it finally quits, it’s because the motor is worn out and can’t develop enough torque to generate the correct fuel pressure. Under normal conditions, it’s not uncommon for a pump to last the whole life of the vehicle. Electric fuel pumps are among the most reliable parts of a car.

Signs of a bad fuel pump module