Hyundai Repair: gas tank splash, hyundai elentra, vent valves

Question
I have A hyundai elentra 2000 GLS, few months ago it began to splash de gasoline when Im filling the tank, I change the canister under the trunk that connect with the some tubings with the gas tank, I check all those tubings to some obstruction, and the check valve in the entrance of the tank too and I saw all in order. do you know something about this kind of problem? Thanks

Answer
If there's nothing obstructing the flow of fuel into the tank, then there's a restriction that's not allowing the vapors to leave the system.  Here are the possibilities:

1.  Sticking fuel tank vent valve
2.  Restricted evaporative hoses
3.  Fuel in canister or canister otherwise restricted (you can cross this off since you've already replaced the canister)
4.  Canister close valve stuck closed
5.  Canister filter obstructed

Your best bet is to probably start at the end of the list and work toward the beginning in your checking.  The tank vent valves are on the top of the fuel tank, so you'd need to remove the fuel tank to check them.