Symptoms of Faulty Fuel Pump in a Vehicle and Its Replacemen


Nov 1, 2012
Fuel pump is an essential element for any vehicle responsible for delivering fuel to the engine. Any malfunction in the fuel pump leads to total disaster of the vehicle. Therefore, drivers need to be aware of the common symptoms of a faulty fuel pump to address the complications at an early stage. Symptoms of a bad fuel pump
The 5 most common symptoms of a faulty fuel pump are as follows: • Engine doesn’t start: This is one of the severe symptoms of a faulty fuel pump. If the fuel pump has disintegrated to the extent where the vehicle doesn’t start, it indicates that there is no fuel reaching the engine upon ignition. Also, check for pressure in the fuel line (indicates 0) and blown out fuse for diagnosing a faulty fuel pump. • Engine sputters at high speed: Engine sputtering is the most common early sign of a faulty fuel pump which usually arises when driving a vehicle constantly at high speed. People usually mistake a sputtering vehicle with some fuel related issue or with dirty gas. The main reason behind engine sputtering is the loss of pressure in the steady supply of fuel to the engine. • Vehicle loses power during acceleration: During the process of acceleration the engine demands for more fuel than usual. But due to its malfunction, it cannot keep on the required pressure to deliver the fuel at constant speed thereby causing the engine to improperly mix air and fuel leading to power loss. • Surging: Surging takes place as the vehicle ages and undergoes wear and tear, thus making the fuel pump resistant within its motor. This creates a condition where the fuel pump will not be able to draw electricity to maintain the pressure required for steady speed and hence may surge with sudden rise in pressure. • Reduced overall engine performance: When a vehicle is put under stress while hauling a load or climbing a hill the weakening factors of the faulty pump begins to take control, and the fuel delivery system will not be able to keep up with the demands, thus leading to reduced engine performance. Procedure to replace a faulty fuel pump • Step-1: Check the tank for fuel and pressure of fuel system • By using fuel gauge, check the amount of fuel in the tank and ensure that it is not more than 1/8 full. • The fuel system pressure is relieved by pulling out the fuel pump relay located in the engine bay fuse box and taking out the gas cap. After removing these items crank your engine and allow it to run until it stalls and shuts down thus enabling your fuel lines to starve of fuel and relieve pressure. • Always make sure that you disconnect the negative battery cable after relieving the fuel system pressure. • Step-2: Access the fuel tank and if necessary remove it • The fuel pump can be accessed from the access point available by simply removing the screws and lifting the cover off. • In case if your vehicle doesn’t have an access point then by using a hydraulic floor jack lift the vehicle and remove the entire tank from beneath the vehicle. • If required remove the entire fuel tank by supporting at its center with a floor jack and pull out the hoses and tubes attached to the tank. After disconnecting, take off the fuel tank mounting braces. • Step-3: Remove the old fuel pump from fuel tank • The old fuel pump from the tank can be removed by disconnecting all electric connections. Make sure that you label the fuel lines to avoid crisscrossing them when re-installing a new pump. • Step-4: Replace the tank with new fuel pump • Attach the new fuel pump in the right manner and reattach the connections and lines. • Re-pressurize the fuel system before cranking by replacing the gas cap, negative battery cable and fuel pump relay. • Turn on the ignition key for a few seconds but don’t crank the engine. Repeat this procedure few times and you are done. Like any aspect of vehicle operation, understanding the fuel pump operation and different ways it fails can help drivers to avoid situations with a failing vehicle. Airtex Fuel Delivery Systems is the leading aftermarket supplier of mechanical and electric fuel pumps and modular reservoir assemblies (MRA). For over 50 years, Airtex fuel pumps have been the benchmark fuel delivery components for leading companies in the automotive aftermarket. If you are looking for an electric fuel pump, visit us at: