* Difficulty starting: This is a classic sign. The engine cranks but struggles to start, or takes several attempts. The problem might be worse when the tank is low, as the pump has to work harder to pull fuel.
* Engine sputtering or hesitation: The engine may sputter, hesitate, or stumble, especially under acceleration or when climbing hills. This indicates an inconsistent fuel supply.
* Engine stalling: The engine might stall unexpectedly, particularly at low speeds or idle.
* Reduced fuel economy: A weak fuel pump may not deliver fuel efficiently, resulting in lower gas mileage.
* Loss of power: A lack of sufficient fuel pressure will noticeably reduce engine power and acceleration.
* Whining noise from the fuel tank: You might hear a whining or buzzing sound coming from the fuel tank area, particularly when the ignition is turned on. This is the sound of the pump straining. However, this isn't always present, as the pump can fail silently.
* Check Engine Light (CEL): While not always indicative of a bad fuel pump itself, a CEL can illuminate due to related problems like low fuel pressure. A diagnostic code read is essential to identify the specific issue.
Important Note: Many of these symptoms can be caused by other problems, such as a clogged fuel filter, faulty fuel pressure regulator, bad mass airflow sensor, or even a failing ignition system. Therefore, it's crucial to have a mechanic perform a proper diagnosis before replacing the fuel pump. Simply replacing the pump without a proper diagnosis could lead to unnecessary expense. They'll likely check fuel pressure to confirm a failing pump.
