This happens every time i try to fuel up.
When pumping gas the fuel spills out after a few seconds. Even though not full. on 2000 Chevrolet Express 1500
Check for obstructions in the fill tube. There is also something in there that prevents fuel vapor from escaping. its part of your EVAP system. That could be malfunctioning.
i think there is a part to keep gas from coming out if veh. is flipped over, might be stuck.