Air Induction and Fuel Distibution

Filtered air from the vehicle's intake ducting is metered by the electronic throttle and then directed via the induction elbow into the intake manifold. The electronic throttle enables the ECM to control the flow of air into the engine.





The induction elbow provides the interface between the electronic throttle and the intake manifold.

There are connections on the induction elbow providing vacuum take-offs for brake servo, cruise (speed) control actuator/fuel pressure regulator and the EVAP system part-load breather. The EGR valve is also connected to the induction elbow or, if not used, a blanking plate is fitted.


Fuel Distribution
Fuel is supplied to the engine by eight fuel injectors (one per cylinder). The injectors are located in two fuel rails which run the length of each cylinder bank and are integral with the air intake manifold.

Fuel pumped from the tank enters a feed pipe at the rear of "B" bank. Fuel flow is along the 'B' bank fuel rail, across the top front of the engine (cross-over pipe) and through the "A" bank fuel rail, the unused fuel returning to the tank by a pressure regulator. Fuel-rail pressure is regulated at 3.0 bar above intake manifold pressure.

The fuel injectors are each controlled electrically from the engine management control module (ECM).

A test valve is fitted to the cross-over pipe connecting the fuel rails at the front of the intake manifold. This valve allows the fuel system to be depressurized during servicing and troubleshooting