The fuel pump is controlled two ways. The ECM — electronic control module — grounds the fuel pump relay when the key is turned on for 2 seconds to bring fuel pressure up quickly for startup.

Overfilling your GM vehicle fuel tank could result in several engine performance issues and fuel system issues, as explained in a recent report.

To finish the fuel tank conversion, with the module in place we added a pair of 3/8 NPT to -6 male fittings for the pressure and return connections and also fitted the power and ground connections ...