* Engine Hesitation or Stalling: This is a classic symptom. The engine might sputter, hesitate, or even stall, especially when accelerating or under load. It might start fine, then die unexpectedly.
* Difficulty Starting: The engine might crank but take a long time to start, or it might start only after several attempts. This is because the fuel pump isn't delivering enough fuel to the engine quickly enough.
* Reduced Engine Power: The engine might feel sluggish or lack its usual power. Acceleration might be noticeably slower than normal.
* Surging or Erratic Idle: The engine might idle roughly, surge, or fluctuate unexpectedly.
* Fuel Pressure Problems (Requires a Gauge): The most definitive diagnosis requires measuring fuel pressure. If you have a fuel pressure gauge, checking the pressure is the best way to confirm a failing fuel pump. Low pressure indicates a problem.
* Whining Noise from the Fuel Tank: You might hear a whining or buzzing sound coming from the fuel tank area, especially when the ignition is turned on. This is the pump trying to work harder than it should. This noise is not always present, however.
* Check Engine Light (with Fuel System Related Codes): While not always directly indicative of a fuel pump, a check engine light, especially accompanied by diagnostic trouble codes (DTCs) related to fuel system issues (e.g., fuel pressure sensor, fuel pump circuit), can suggest a problem. A code reader is necessary to see these codes.
Important Note: Some of these symptoms can be caused by other problems, such as a clogged fuel filter, faulty fuel injectors, or a problem with the ignition system. Therefore, it's crucial to have a mechanic diagnose the issue properly before replacing the fuel pump. Replacing the fuel pump is usually a labor-intensive job, so it’s best to avoid unnecessary replacements.
