The fuel supply is stored in the fuel tank. An electric fuel pump, attached to the fuel sender assembly (inside the fuel tank) pumps fuel through an in-line filter to the throttle body unit or fuel rail. The pump is designed to provide fuel at a pressure above the regulated pressure needed by the throttle body unit or fuel rail. Unused fuel is returned to the fuel tank by a separate pipe.
Unleaded fuel must be used with all gasoline engines for proper emission control system operation. Using unleaded fuel will also decrease spark plug fouling and extend engine oil life. Leaded fuel can damage the emission control system, and its use can result in loss of emission warranty coverage.