injection valves which are hydraulically operated in the usual way by
the high pressure fuel. The control units, exploiting quick-acting Sulzer
solenoid rail valves, regulate the timing of fuel injection, control the
volume of fuel injected, and set the shape of the injection pattern.
The three fuel injection valves in each cylinder cover are separately
controlled so that, although they normally act in unison, they can also
be programmed to operate separately as necessary. The key features
of the common rail system are defined as: