High-Pressure Oil Flow
During cold starts, the high-pressure oil pump (6600) receives oil from the left side valve lifter oil gallery possibly through the short circuit valve. Once the engine starts or during warm engine starts, the short circuit valve closes and the high-pressure oil pump receives filtered oil from the high-pressure oil pump reservoir. The high-pressure oil pump pumps the oil under extremely high pressures (2,758-20,577 kPa) through the left and right side high-pressure supply hoses to the high-pressure oil rails (integral to the cylinder heads). Once in the oil rail, the oil is fed to the fuel injector bores through four oil feed galleries drilled and machined in the cylinder head. The high-pressure oil then actuates the fuel injectors. The IPR valve controls and maintains the high-pressure oil. The PCM uses the information from ICP sensor to adjust the pressure in the system.