What is a common symptom of a failing fuel pump?

A common symptom of a failing fuel pump is difficulty starting the engine. When a fuel pump begins to fail, it may not deliver the necessary amount of fuel to the engine, which can lead to hard starting or a complete inability to start. The fuel pump is crucial in maintaining the proper fuel pressure needed for the engine to operate effectively; if it cannot provide the fuel consistently or at the required pressure, the engine struggles to start or may crank but fail to fire up.

In contrast, increased fuel efficiency, unchanged engine performance, and quick acceleration response would indicate that the fuel system is functioning well. Therefore, the presence of difficulty starting clearly points to an issue with the fuel pump, making it a key symptom of failure.