High Pressure System
WARNING: This page is about a different car, the 2007 GMC Sierra, 2007 GMC Cab & Chassis Sierra, 2007 Chevrolet Silverado, and 2007 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The fuel injection pump at the front of the engine valley includes a fuel supply pump and a high-pressure pump. Fuel is drawn by the fuel supply pump from the primary fuel tank and delivered to the high-pressure pump. The pump is engine-driven by the camshaft gear. High pressure fuel is regulated by the fuel pressure regulator mounted on the fuel injection pump. From the high-pressure pump, the fuel moves to the left and right fuel rails through high pressure metal lines. Each fuel rail distributes high pressure fuel to one bank of 4 fuel injectors. The fuel pressure relief valve is location on the left rail, and relieves excessive fuel pressure which returns to the fuel tank.