I would remove your new filler neck and check inside for the old inner liner and see if it is causing an obstruction when filling.
Yes, it is a venting issue but first, you need to be sure there is nothing blocking the fuel from going into the tank when filling.
1. Drain fuel to a level (approximately 3/4 full) below the fuel tank filler connection by using the fuel hose at the fuel pump to fuel tube connection.
2. Detach fuel filler pipe from support bracket and disconnect fuel filler and vent hoses.
3. Loosen clamp attaching filler pipe and disconnect hose from the pipe, pulling the internal fuel tube from tank filler neck.
4. Remove the three retainer screws that attach the filler pipe flange to the body fuel filler housing.
5. Remove fuel filler pipe from vehicle.
6. Remove hose and clamps. Replace all damaged or worn parts.
Saturday, May 29th, 2021 AT 11:17 AM