The telltale signs of a bad fuel pump include sluggish acceleration, a high-pitched sound when the engine is first started, engine misfires, engine stalling and an engine that will not start at all. An automotive fuel pump is a mechanical or electrical device, and its main function is to supply a steady stream of pressurized fuel into the engine.
According to Cars Direct, the most common symptoms are failure of the engine to start and stalling. Malfunctioning fuel pumps cannot hold sufficient fuel pressure to start and keep the engine running. Intermittent decreased acceleration is also attributed to a bad pump because it cannot maintain an even flow of fuel to the engine, especially when the car is under heavy load, climbing a hill or running at highway speeds.
Automotive fuel pumps are designed to be submerged in gas, and empty gas tanks or failing fuel filters can cause pumps to fail prematurely.
Failed pumps cause other engine components to work harder, and a vehicle that shows signs of a failing fuel pump must be immediately checked by a qualified mechanic. Failure to replace the malfunctioning pump in a timely manner can lead to getting stranded at the side of the road at the worst possible time, according to Auto Hub 360.