Fuel From Evap Canister

I have this 88 GTA and the owner before me installed a fuel pump. He also told my he had a vaper problems and replaced the gas cap. Now the car has been sitting for a year, now when the car is running and is shut off, gas comes out of the evaporative canister. Can anyone help me with this before I spend too much time with this. THANK YOU!!!!!

I know usually if you overfill your gas tank, fuel can get to the evap. can. If it has been sitting you may want to check the tank and the fuel filter, and check all the lines to make sure he put everything back the way it is supposed to be. You are gonna have to replace the filter and shit in the evap can...