What is a common symptom of a failing fuel pump?

A common symptom of a failing fuel pump is engine stalling. The fuel pump is responsible for delivering a consistent supply of fuel to the engine; if it begins to fail, it may not provide enough fuel, leading to situations where the engine can stall or hesitate during operation. This can occur particularly under demanding conditions, such as acceleration or when climbing hills, due to the engine not receiving the required amount of fuel.

The other choices represent scenarios that would not typically be associated with a failing fuel pump. For instance, increased fuel efficiency and improved acceleration suggest that the engine is receiving adequate fuel supply and operating optimally, which is contrary to what happens when a fuel pump is failing. Similarly, reduced noise may imply that the fuel pump is functioning well since failing pumps often become noisier as they struggle to draw fuel. Understanding this helps in diagnosing issues with fuel delivery systems in vehicles.