* Engine won't start: This is the most obvious symptom. The engine cranks but fails to ignite because no fuel is reaching the engine.
* Difficulty starting (especially when hot): The fuel pump might be weakening, and struggles to provide enough pressure when the fuel is hotter. It might start after several attempts.
* Stalling: The engine might stall unexpectedly, especially when accelerating or idling. This happens because the fuel supply is inconsistent or insufficient.
* Hesitation or sputtering: The engine may hesitate or sputter during acceleration, indicating inconsistent fuel delivery.
* Loss of power: A weak fuel pump can't supply enough fuel to meet the engine's demands under load, resulting in a loss of power, especially during acceleration.
* Surging: The engine may surge or hunt for idle speed, indicating fluctuating fuel pressure.
* Weak acceleration: Similar to loss of power, the car will accelerate slowly and sluggishly.
* Fuel pressure problems (requires testing): This is a definitive symptom requiring a fuel pressure gauge to check actual fuel pressure. Low fuel pressure confirms a weak or failing fuel pump.
* Whining noise from the fuel tank (sometimes): You might hear a whining sound coming from the fuel tank area, especially when the ignition is turned on. This is not always present but can be an indicator.
Important Note: Some of these symptoms can also be caused by other issues, such as a clogged fuel filter, faulty fuel injectors, or problems with the ignition system. Therefore, it's crucial to diagnose the problem properly before replacing the fuel pump. A mechanic can use a fuel pressure gauge to accurately determine if the fuel pump is the culprit.
