A bad fuel pump has symptoms that mimic other ignition- and performance-related problems in a motor vehicle. You must listen to your car very carefully to identify the subtle differences in engine performance that are caused by a failing fuel pump to better assist your mechanic when describing the problem. If not handled quickly, a failed fuel pump can lead to damaged fuel injectors, which greatly raises the cost of repair.
A damaged or failed fuel pump can cause a Grand Am to be unable to start. The engine cranks (noise of the engine attempting to turn over), but the vehicle is unable to send fuel to the engine to start it. This is often the case when the fuel pump has failed entirely and is unable to maintain fuel pressure into the engine.
Low fuel pressure causes a rough idle for the engine. You will experience dipping RPMs and a shake in the engine block when the car is sitting still, which leads to engine misfires when the vehicle is accelerating and attempting to retain speed. A Grand Am's fuel injectors are highly sensitive to fuel pressure, so these signs could emerge very early in the fuel pump's failure.
A failing fuel pump may deliver satisfactory fuel pressure though not enough fuel volume. As a result, you will experience loss of power when the vehicle is accelerating heavily, is under load or cruising at highway speeds. Engine sputtering may also occur while this is happening, and the car produces a sound that is noticeable.
