I recently replaced my fuel cap and was driving from 5000 ft to 12000 ft and my car died out. The gas gauge went to empty. I loosened the cap and a lot of backpressure was released. The ol girl ran fine after that. Could it be something other than the fuel cap? Its a 2001 Ford Expedition with 178K miles
It is probably the EVAP system/charcoal canister and its tubing that have a problem. Are you in the habit of over filling the tank after the pump clicks off? That could have damaged the system.