Symptoms of a failing fuel pump include increased fuel consumption, gasoline odor in the vehicle, reduced engine power and acceleration, engine stops running during operation, car is hard to start or won't start, check engine light with a low fuel-pressure code and a whining noise from the gas tank.
Fuel pumps on modern cars are almost always located in the gas tank. In front-engine vehicles, the fuel is pumped the length of the car to the fuel injectors in the engine. To accomplish this, the fuel pump has to maintain high fuel pressure so the fuel injectors can operate at very specific intervals. As a pump begins to fail, this lack of fuel pressure can cause the vehicle to stop while operating, or surge erratically as the fuel injectors spray in varying amounts or at irregular intervals.
A failing fuel pump can also make a car difficult or impossible to start. Modern cars have several systems in place that can disable them from starting successfully. These could range from security systems to a neutral safety switch in the transmission. Because of this, mechanics look for several symptoms of a failing fuel pump before deciding that is a car's main problem.
Other symptoms to look for are increased fuel consumption, weak engine performance, a whining sound coming from the gas tank and a whining sound when the ignition is turned to the "Ready" position before the starter is engaged. A strong smell of gasoline can be a sign that the fuel pump's relief valve isn't operating properly and is flooding the engine. Several of these symptoms spotted together are good reason to take a vehicle in for servicing.