I have a 08 avalanche that I can not fill with gas . No check engine lights or stored codes .Fill tube has been removed and nothing found in tube .Evap charcoal canister has been replace because that's what I thought was issue (no fix ).Replaced solenoid valve even though I can blow air with no restrictions ( no fix ). All I can find is everyone keep saying vent lines and evap system . I am trying to find out where the fill tube connects to tank is there a check valve . I ask this because when I removed the fill tube off t the tank it has a moving piece inside that I can move around with my finger but I can not push it open and thinking this is some kind of spring load inlet to tank that is broke and not opening to let fuel in ,

 

anyone ?

 

Hello??