* Clogged Vapor Canister: This is the most common culprit. The vapor canister filters gasoline vapors. If it's clogged, pressure builds up in the fuel tank, triggering the pump to shut off as a safety precaution to prevent spillage.
* Faulty Vapor Canister Purge Valve: This valve controls the flow of vapors from the canister to the engine for combustion. A malfunctioning valve can cause a pressure buildup in the tank.
* Leaking Fuel Cap: A loose or damaged gas cap allows air to enter the system, disrupting the pressure balance. This is a simpler and cheaper fix than other issues.
* Blocked Fuel Tank Vent Line: The vent line allows air to enter the tank as fuel is removed, equalizing pressure. A blockage prevents this, leading to a vacuum and causing the pump to shut off.
* Problems with the Fuel Tank Pressure Sensor: A faulty sensor might incorrectly signal a pressure buildup, even if none exists.
* Rarely: Damaged Fuel Tank: In very rare instances, a damaged fuel tank could contribute to pressure issues, but this is less likely.
What to do:
1. Check the gas cap: Ensure it's tightly closed. Try filling again. If this solves the problem, you've found the culprit. Replace the cap if it's damaged.
2. Inspect the fuel cap seal: If the cap itself is fine, the seal around it might be compromised.
3. If the gas cap isn't the issue: You'll likely need a mechanic to diagnose the problem. The vapor canister, purge valve, vent line, or pressure sensor are more difficult to check without specialized tools and knowledge. They may need to perform diagnostics to identify the exact problem.
Ignoring the problem could lead to more serious issues, so it's best to have it checked sooner rather than later.
