LR3/Disco 3
Eight, top fed, eight hole, fuel injectors are installed in the fuel rails. The injectors are electromagnetic solenoid valves
controlled by the ECM. Two O-rings seal each injector to manifold interface. The fuel jets from the injectors are directed
onto the back of the intake valves. For additional information, refer to
Electronic Engine Controls
(303-14B Electronic
Engine Controls - 4.4L)
VARIABLE VALVE TIMING (VVT)
The continuously VVT unit turns the intake camshaft in relation to the primary chain to advance and retard the timing.
The system improves low and high-speed engine performance, engine idle quality and exhaust emission.
The VVT system changes the phasing of the intake valves, relative to the fixed timing of the exhaust valves, to alter:
the mass of air flow into the engine's cylinders,
and the engine's torque response and emissions.
The VVT unit uses a vane device to control the camshaft angle (refer to VVT operation). The system operates over a
range of 48° and is advanced or retarded to the optimum angle within this range.
The ECM controls the VVT, using engine speed and load, and engine oil temperature signals to calculate the appropriate
camshaft position. For additional information, refer to
Electronic Engine Controls
(303-14B Electronic Engine Controls -
4.4L)
The continuous VVT system provides the following advantages:
Reduces engine emissions and fuel consumption by further optimising the camshaft timing, this improves the
engine's internal exhaust gas re-circulation (EGR) effect over a wider operating range
Improves full-load torque characteristics as the camshaft timing is optimised at all engine speeds for superior
volumetric efficiency
Improves fuel economy by optimising torque over the engine's speed range.
This system also has the added benefits of operating at a lower oil-pressure and faster response time when compared to
a non-VVT system.
Variable Valve Timing Operation
