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303-14-10 Powertrain Control Management 303-14-10 DESCRIPTION AND OPERATION (Continued) Fuel Pressure Regulator Fuel Injector The fuel pressure regulator is attached to the outlet side of the fuel rail and controls the pressure within the fuel rail. Fuel is delivered to each injector at the same pressure to ensure the volume of fuel injected is equal for each cylinder. One side of the diaphragm senses fuel pressure, and the other side is connected to the intake manifold vacuum. Fuel pressure is established by a spring pre-loading applied to the diaphragm. Balancing one side of the diaphragm with manifold vacuum maintains a constant pressure across the fuel injectors. Excess fuel is bypassed through the regulator and returned to the fuel tank. Fuel pressure is high when engine vacuum is low. Intake Air System The intake air system provides clean air to the engine, optimises airflow and is designed to minimise induction noise. The intake air system consists of: Air Cleaner Assembly Air Cleaner Assembly The air cleaner assembly is an essential component of the intake air system. The air cleaner assembly houses a disposable air filter element that removes Item Description dust from the intake air. The air cleaner element must be periodically replaced according to the maintenance 1 O-ring schedule. 2 Filter 3 Adjusting Sleeve Air Mass Measurement System 4 Weld The I6 and V8 engines use the “speed density” fuel 5 Shells (2 of) injection system. In this system, the PCM has stored in its memory the theoretical mass of intake air that 6 Weld will be drawn into the engine at any given speed of 7 Weld operation. Using the engine speed sensor (Crankshaft 8 Support Ring Position CKP) signal, the Intake Air Temperature and Manifold Absolute Pressure sensor (T-MAP), the PCM 9 O-ring can compute the intake air mass, and from it the fuel 10 Seat & Spray Plate Assy. required to be injected into the engine for combustion. 11 Tube Assy. This amount of fuel injected is further corrected by 12 Needle, Ball & Armature Assy. feedback information obtained from the Heated Oxygen Sensor (HEGO) sensor, providing close loop 13 Spring control of fuel injection. A further feature of this 14 Coil & Bobbin Assy. system is the ability to ‘re-calibrate’ itself for changes 15 Plastic Body in fuel requirements as the engine wears and the sensors age. This is known as adaptive strategy or learning and is an additional function derived from HEGO sensor information. G98122 en |