• The warm-up acceleration function accelerates engine warm-up by varying the engine’s idling speed in accordance with the engine’s coolant temperature. It can operate either automatically or manually. Selection is made using the idling speed adjustment potentiometer.
• The fuel injection pressure is calculated from the fuel injection quantity and engine speed.
(1) Main injection timing • The main injection timing is calculated from the fuel injection quantity and engine speed. (2) Pilot injection timing (pilot interval) • The pilot injection timing is calculated from the fuel injection quantity and engine speed.
(1) Fuel injection quantity during engine startup • During engine startup, the fuel injection quantity is determined in accordance with the engine speed and coolant temperature. (2) Basic fuel injection quantity • The basic fuel injection quantity is determined in accordance with the engine speed and throttle opening. (3) Maximum injection quantity • The maximum… Read More »
(1) Pilot injection • Pilot injection entails the injection of an extremely small amount of fuel ahead of the main injection. • Pilot injection suppresses heat generation early in the injection cycle and thus suppresses NOx generation and noise at the start of combustion. (2) Split injection control • Split injection entails the injection of… Read More »
(1) Operation (1.1) Injection not taking place • With the magnet not energized, the armature plate is pushed up by the valve spring such that the ball seat is closed. • The high-pressure fuel acts upon the control chamber via orifice Z. The same pressure acts upon the nozzle needle. • The fuel pressure acting… Read More »
• The common rail distributes to the injectors high-pressure fuel that has been fed from the supply pump. • Each flow limiter prevents an abnormal outflow of fuel. It does so by blocking the fuel passage in the event of fuel leakage from the injection pipe or excessive injection of fuel from the injector. •… Read More »
(1) MPROP (rail pressure control valve) • The MPROP receives fuel from the feed pump and feeds fuel toward the plungers of the supply pump in such a quantity that the fuel pressure (target common rail pressure) corresponds to that required by the engine electronic control unit. • When the MPROP is not operating, i.e.,… Read More »
• In the common rail system, an electronic control unit monitors various aspects of the engine (engine speed, throttle opening, coolant temperature, etc.) using information from sensors. In accordance with these data, the electronic control unit effects control over the fuel injection quantity, fuel injection timing, and fuel injection pressure in order to optimize the… Read More »