I have an 03 blazer xtreme and starting a week ago when i fill up the tank it stops at about 7/8 full and the pump shuts off and it spits gas back up the filler neck and when i pull the pump out of the filler neck i can hear it gargling down the filler neck. The fuel pump is new and ive changed the canister vent valve on the tank but i now realize the vent valve i bought was for a 4 door not a 2 door. I dont know if that makes any difference cause i replaced it bout 2 months ago and it just started having this issue. Any help would be much appreciated.