1. Gas Cap Issues:
* Loose or improperly seated gas cap: This is the most common and easiest to fix. Ensure the gas cap is securely tightened. A faulty gas cap can prevent proper venting, creating a vacuum that prevents fuel from entering.
* Damaged gas cap: The gas cap itself might be cracked or damaged, preventing a proper seal. Replace it if necessary.
2. Fuel Filler Neck Problems:
* Obstruction in the filler neck: Something might be blocking the fuel filler neck, such as ice (in cold weather), dirt, debris, or even a small animal. Try carefully inspecting the filler neck with a flashlight.
* Kinked fuel filler hose: The hose connecting the filler neck to the tank could be kinked or damaged, restricting fuel flow.
3. Fuel System Issues:
* Clogged fuel filter: A clogged fuel filter restricts fuel flow to the engine. This is less likely to completely prevent filling, but could slow it down significantly.
* Faulty fuel pump: A failing fuel pump might not be able to create enough pressure to overcome a minor obstruction, preventing fuel from entering the tank. This is less likely to prevent filling entirely unless the pump is completely failed.
* Problems with the fuel tank vent system: A clogged or malfunctioning vent system prevents air from entering the tank as fuel is added, creating a vacuum. This is a common reason why a car won't take gas. The vent system might be located on the fuel tank itself, or in a separate area.
* Debris in the fuel tank: In rare cases, debris in the fuel tank can obstruct the fuel inlet.
* Evaporative Emission Control (EVAP) System issue: This system controls fuel vapors, and a malfunction can sometimes affect fuel filling. A diagnostic code reader might be needed to diagnose this.
4. Other Possibilities:
* Incorrect fuel nozzle: Are you using the correct type of nozzle (regular, mid-grade, premium)? Using the wrong one *might* prevent gas from flowing if the nozzle doesn't properly fit into the fuel filler neck.
* External damage: Inspect the area around the fuel filler neck for any signs of damage or tampering.
Troubleshooting Steps:
1. Start with the simplest: Check the gas cap first. Make sure it's properly seated and not damaged.
2. Inspect the filler neck: Use a flashlight to carefully look for obstructions.
3. Listen carefully: As you try to fill the tank, listen for any unusual sounds that might indicate a blockage.
4. Try a different gas station: Sometimes, the problem might be with the gas pump itself.
5. Consider professional help: If you can't identify the problem, take your Blazer to a qualified mechanic. They will have the tools and expertise to diagnose the issue properly.
Safety Note: Always exercise caution when working around fuel. Avoid sparks or open flames. If you smell fuel, stop and seek professional assistance.
