Common Symptoms:
* Engine cranks but won't start: This is the most common and obvious symptom. The engine turns over, but it doesn't fire up because the fuel pump isn't delivering fuel to the engine.
* Hesitation or sputtering: The engine may run rough, hesitate, or sputter, especially under acceleration. This indicates the fuel pump may be weak and struggling to keep up with demand.
* Loss of power: Similar to sputtering, the car may lose power or struggle to accelerate, especially uphill or when under load.
* Engine stalling: The engine may stall unexpectedly, particularly when idling or after accelerating.
* Surging: The engine may unexpectedly rev up and down without any input from the accelerator.
* Weak fuel pressure: This requires a gauge to measure fuel pressure at the fuel rail. Low pressure confirms a fuel pump issue (you'll need a fuel pressure gauge and know how to connect it properly to do this check).
Less Common/Indirect Symptoms:
* Whining noise from the fuel tank: A failing fuel pump can sometimes make a whining or buzzing sound when the ignition is turned on. This is due to the pump struggling. This is not always present.
* Smell of fuel: A leaking fuel pump can result in a strong smell of gasoline. However, this isn't as common a symptom of a *failing* fuel pump as the others.
Important Note: Many of these symptoms can be caused by other issues, such as a clogged fuel filter, a bad fuel pressure regulator, faulty ignition components, or even a problem with the computer. It's crucial to have a mechanic diagnose the problem properly to ensure the fuel pump is the actual culprit before replacing it. Simply replacing the fuel pump without proper diagnosis might lead to unnecessary expense.
