GMC Troubleshooting Questions? Ask a Mechanic for Answers
I am sorry for the long wait
99 % of these that will act up only when fuel is added is an issue with the fuel pump modules in the tank with either the pump failing or the return/vent part of the pump assembly bad and it actually allowing fuel into the vapor hoses in the tank and causing this problem
usually replacing the fuel pump module assembly in the fuel tank corrects this type of issue
how are you making out ?