robbrad4d

This is an evap canister problem. As fuel tries to enter the tank the air/vapor inside the tank has to escape through the evap canister to be filtered before leaving the system. Dust and dirt constantly clog these canisters on GM vehicles due to poor design. Fuel cannot enter the tank efficiently if the air cannot escape. That is why leaving half the nozzle out is helping because the vapors are able to escape around the fill nozzle. Several youtube videos on how to fix this or bypass