When you are filling-up, do you have the black rubber anti-splash shield of the gas nozzle completely tight up against the fill pipe??? If so, it leaves no room for the air to escape when refueling and can sometimes cause the nozzle to click-off as thinking it's already full. Try leaving a small gap of space between the end of the fuel tank opening and the black rubber splash shield of the nozzle to allow the air to escape easily. Hope this info helps.