Got an 03 GMC sierra that will spin over but wont start. Only code showing was a security code for no fuel P1626. I disabled the vats through hptuners and still wont start. It has 55-60psi while cranking and has spark at the plugs(only checked 3 plugs). Plug fires at the same time as compression hits. Wont hit a lick on starting fluid. With a test light the injectors show to be firing. Any ideas what to do next?