This is why I don't fill up at Sheetz...for some reason it always happens at every pump there. Once you find a way that works, keep with it and enjoy your Mustang!

 

Check out this post. Maybe what you're looking for.

 

Very interesting and sounds right. I wonder if there is a way of cleaning out the fuel vent line with a wire or pressurized air? Where does the vent come in the fuel fill opening? Up top? I suppose I can feel around for it...

 

I've never had this problem at all..Guess I've been lucky