Common Signs:
* Engine won't start: This is a classic symptom. You turn the key, you hear the starter crank, but the engine fails to ignite. This is often accompanied by a "whirr" sound from the fuel pump for a fraction of a second, then silence. If the pump isn't priming, the engine has no fuel.
* Hesitation or sputtering: The engine hesitates or sputters, especially when accelerating or under load. This indicates an inconsistent fuel supply.
* Loss of power: Similar to sputtering, the engine might lose power, especially during acceleration. This suggests the pump isn't supplying enough fuel to meet the engine's demands.
* Engine stalls: The engine randomly stalls, especially when idling or after running for a while. This points to an intermittent fuel supply issue.
* Weak fuel pressure: This requires a gauge to measure fuel pressure at the fuel rail. Low pressure indicates a failing pump. A mechanic would typically perform this test.
* Loud humming or whining noise from the fuel tank: You might hear unusual noises emanating from the fuel tank area, especially when the ignition is turned on. This could be the fuel pump struggling.
* Surging: The engine revs erratically, speeding up and slowing down on its own.
Less Common, but still possible Signs:
* Fuel smell: A strong fuel smell can indicate a leak somewhere in the fuel system, possibly related to a failing fuel pump seal.
Important Considerations:
* Fuel filter: A clogged fuel filter can mimic many symptoms of a bad fuel pump. It's crucial to check and replace the filter *before* condemning the pump.
* Other fuel system components: Issues with the fuel pressure regulator, injectors, or fuel lines can also cause similar problems. A proper diagnosis might require a professional mechanic.
How to proceed:
1. Check the fuel filter: This is the cheapest and easiest thing to check first.
2. Listen for the fuel pump prime: Turn the ignition key to the "on" position (without starting the engine). You should hear a brief humming sound from the fuel tank area. If you don't, the pump might be faulty.
3. Check fuel pressure: This requires a fuel pressure gauge and some mechanical knowledge. It's best left to a professional mechanic.
4. Visual Inspection (Advanced): Accessing the fuel pump usually requires dropping the fuel tank; this is not an easy task for most DIYers. If you're comfortable doing this, you can visually inspect the pump for damage.
If you are not comfortable working on your fuel system yourself, take your Blazer to a qualified mechanic. Working with fuel can be dangerous if not done correctly. They have the tools and expertise to diagnose the problem accurately and efficiently.
