Hyundai Repair: fueling, tank case, canister filter

Question
When fueling the gas pump pops off like the tank is full. We have two Accents 2000 & 2001 both do it.

Answer
There are two basic types of problems that can cause this:

1.  Restriction preventing fuel from entering the tank.
2.  Restriction preventing fuel vapor from venting out of the tank.

Case #1 is rare but is simple to check while checking for potential causes of case #2.

First, start with a visual inspection.  All the fuel and vapor hoses and pipes should be open and free of kinks.  The fuel tank should not be abnormally bent.  Presuming these items are okay, the most likely issue is that the canister filter is restricted to the point that the canister cannot vent to fresh air.  If you want to go through and check for certain, go to the location where the canister filter vents to air and one by one disconnect items.  When disconnecting an item allows you to normally refuel, you've found the restricted item.