i have an A100 slant six pickup. Two times now after driving, fuel is spitting out from the filler neck. This doesn't happen when filling the tank only while or after driving the truck. Once while I was at a stoplight and a guy told me my truck was spitting out gas, another after a short 5 mile drive and parked in my driveway with the engine shut off. I noticed the drops of gas leaking from the gas cap both times. When I released the cap, the gas gushed out. Not sure why this is happening and wonder if anyone knows the cause. Thanks