Q: Gas meter always says full won't allow me to put full up on gas what can I do??

Hi There, It sounds like you may have two separate issues going on here. Your fuel tank sending unit is a unit that monitors the fuel level in your tank. When this is not working properly, you may notice erratic readings on your fuel gauge. Secondly, your issue with refueling the tank sounds like you have a problem with what is called a purge valve solenoid which is part of your evaporative emissions system.

The EVAP system prevents fuel vapors from the fuel tank from escaping into the atmosphere, which collects and temporarily stores the fuel vapors in a charcoal canister. The charcoal canister is filled with activated carbon pellets that can absorb the fuel vapors. When the engine is running, the fuel vapors are purged from the canister and burned in the engine. The vent control valve (solenoid) controls the flow of outside air in and out of the charcoal canister. When this is not working properly, you may experience the gas pump shutting off prematurely causing it to take a very long time to fill up your fuel tank. This is due to the excess fuel vapor that is present when the purge solenoid is not working properly by releasing these vapors. The gas pumps at the fuel station have automatic sensors on them (for safety reasons) that shut off automatically when too much fuel vapor is present. I would recommend having an expert from Your Mechanic come to your home to take a look at your car to diagnose your EVAP purge solenoid.