Fuel injection system and method for a diesel or stratified charge engine

An electrically controlled high pressure fuel injector system for an internal combustion engine having plural cylinders and a crankshaft, comprising:

• a low pressure fuel supply line connected to a supply of fuel;
• a high pressure pump connectable to said low pressure fuel supply line and said supply of fuel;
• a high pressure common rail coupled to said high pressure pump to receive pressurized fuel from said high pressure pump and the fuel supply;
• a plurality of electrically controlled fuel injectors, each coupled to said common rail and responsive to an injector signal to selectively supply fuel from said common rail directly into one of the cylinders;
• a first pressure regulator coupled to said common rail, said pressure regulator being responsive to a pressure control signal to vary the fuel pressure in said common rail;
• a pressure sensor coupled to said common rail to generate a pressure signal indicative of the measured pressure of fuel in said common rail;
• a load sensor which generates a load signal indicative of the position of a control mechanism that controls the engine output;
• a speed sensor which generates a speed signal indicative of engine speed;
• a shaft position sensor which generates a shaft position signal indicative of the angular position of the crankshaft;
• a sequencing sensor which generates a sequence signal that is indicates which of said fuel injectors is to receive the next injection signal;
• an electronic control unit coupled to control said pressure regulator and each of said fuel injectors, said electronic control unit being responsive to said load sensor, speed sensor, shaft position sensor, and sequencing sensor to generate the injection signals and being responsive to said load sensor, speed sensor, and pressure sensor to generate the pressure control signal;
• a second pressure regulator attached to said low pressure fuel supply line and coupled to said electronic control unit, said second pressure regulator being responsive to a low pressure control signal generated by said electronic control unit to vary the pressure of fuel in said low pressure fuel supply line;
• and
• a second pressure sensor coupled to said low pressure fuel supply line to supply a low pressure signal to said electronic control unit indicative of the measured pressure of fuel in said low pressure fuel supply line, said electronic control unit being responsive to the low pressure signal to generate the low pressure control signal.