air in fuel tank

Do you have a vented cap ? My '83 has one. My old '78 did not.
Have you modified any of vacuum and emission lines ?

check your vent line, that should be the third line out of your tank. sometimes it could get clogged. i dont know if you have mud dobber wasps where you are they will build a nest in the vent tube.

Vent not really air just vent problem

I think you are supposed to have air in the tank. It is not a sealed system. I think you either need a vented cap or vent line.

ok, so the vent must not be working properly. i don't believe the cap is a vented one. i did put in a new gas tank a while ago that came with the vent valve and hose on it, so i just used them. maybe that little hose is clogged and i just didn't check it.

I never heard of the fuse thing, but I do know that it will affect the gauge on a newer vehicle. Will not show full for a period of time, unless you shut it off and then back on.

there is supposed to be air in the tank. i helps keep the fuel vapors from going out your cap. that's basically how Chilton described the system...

Depending on weather conditions & amount of fuel you have in tank. The air released from your tank when you take off gas cap will vary.. There are times I get a big whoosh & sometimes nothing @ all... Humidity,air pressure,temp,amount of fuel, how much driving you've done all play a roll in the whoosh factor.. It is also one of the reasons you shouldn't smoke @ a gas pump.. Yes I'm sure you & hopefully everyone here knows. But we've all seen the stupidest videos where someone is smoking while filling up & whoosh up in flames..

that's also why you shouldn't be on your cell phone either. they suggest you shut the vehicle off for another reason. (i know not related) i found out at the dealership, newer fords (at least the trucks) blow a fuse if you fill up while running. it was designed to do that...