LR3/Disco 3
The major components of the fuel charging and control system comprise an intake manifold, a fuel pump, a fuel rail and
eight injectors. The fuel pump supplies fuel from the tank at a constant pressure, via a pipe routed along the side of the
transmission, to the fuel rail. The fuel rail distributes the fuel equally to each of the eight injectors. The fuel injectors, which
are controlled by the Engine Control Module (ECM), are installed in the fuel rails on each side of the intake manifold. A
cross over pipe connects the two fuel rails together at the front of the manifold. A Schraeder valve provides a pressure
test connection for maintenance.
INTAKE MANIFOLD
The intake manifold is located on top of the engine between the two cylinder banks and is manufactured from a composite
material. The manifold comprises a central chamber with eight tracts leading to the inlet ports on the engine. The air
intake manifold is secured to the cylinder heads via 10 bolts.
Rubber gaskets, located in channels in the intake manifold, seal the joints between the ducts and the cylinder heads. For
additional information, refer to
Intake Air Distribution and Filtering
(303-12B Intake Air Distribution and Filtering - 4.4L)
FUEL PUMP
The submersible electric fuel pump is attached to a carrier and is located at the bottom of the swirl pot inside the fuel tank.
The fuel pressure regulator, which controls the fuel pressure in the feed pipe to fuel rail, is located in the fuel manifold in
the fuel tank. For additional information, refer to
Fuel Tank and Lines
(310-01B Fuel Tank and Lines - 4.4L)
THROTTLE BODY
The electronic throttle body controls the engine torque and is located on the air intake manifold. It's main components are,
an electronic throttle control valve, Accelerator Pedal Position (APP) sensor and the ECM.
The APP sensor determines the driver demand to control throttle opening. This value is received by the EMS and the
throttle is then opened to the correct angle by means of an integral electric motor. Sensors in the throttle body are used to
determine the position of the throttle plate and the rate of change in its angle. For additional information, refer to
Electronic Engine Controls
(303-14B Electronic Engine Controls - 4.4L)
Induction Elbow
The induction elbow provides the interface between the electronic throttle body and the intake manifold. Connections on
the induction elbow provide vacuum take off's for various vehicle systems. A boss on the rear of the elbow accommodates
the Exhaust Gas Recirculation (EGR) valve.
FUEL RAIL
