Fuel System Operating Modes
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The fuel tank stores fuel supply. A mechanical fuel injection pump, located below engine intake, draws fuel through the fuel injector control module and fuel filter. The fuel is used as a coolant for the fuel injector control module. Fuel pump output is controlled by the ECM and provides fuel at the pressure needed by the fuel injectors. Fuel injectors supply fuel directly to the engine combustion chambers. A separate pipe returns unused fuel through a fuel cooler and to fuel tank.