GMC Troubleshooting Questions? Ask a Mechanic for Answers
I am sorry for the long wait
once it starts with starting fluid the truck runs fine ?
no codes are being set ?
as soon as the the key is turned ON the PCM will prime or run the pump for 2 seconds then shut off then run when cranking over the engine
when it is acting up with the key OFF if you put your fingers on the fuel pump relay then turn the key ON do you feel the fuel pump relay click on for 2 seconds then click off ?