I have been fighting a fuel delivery issue for a year. I was given a 1986 Ford Holidaire motorhome that is in excellent condition. Both fuel tanks and pumps have been replaced. The problem I have is when I put the gas pump nozzle in to fill the tank it immediately shuts off and spills gas out! In order for me to fill I have to feather the gas nozzle to run very slowly. Needless to say this makes for a very long fill time as I have both tanks to fill. Any ideas?
Look to see if there is a hose that connects near the top of the gas tank and near the top of the filler tube. If so look to see if it has a sag in it that would hold a gas much like a trap in a sink drain, if so do something to eliminate the sag. That hose is for vent the tank, and the sag holds gas and plugs the vent.
IMO, you have a problem with your vapor recovery system. Itโs possible that you saturated the charcoal bed. Itโs also possible that your vapor return from the fill pipe edge to the tank is plugged or the line kinked.
Its probably best to not overfill your tank when you do fill up. When it clicks 'off' do not choke it to try to add another 1/2 gal .