Abstract: A fuel injection system having a fuel injection pump with an electrical control valve for controlling the fuel injection timing and quantity, an electrical control unit (ECU) for storing certain data, including certain master calibration data, for regulating the operation of the control valve, a pump mounted, electrical module having a male connector for connecting the pump mounted module to the ECU, and a printed circuit board mounted on the male connector pins, the printed circuit board having a calibration resistor for establishing an electrical calibration value at one of the pins for adjusting the master calibration table for adjusting the fuel injection quantity.

Abstract: An electrical control unit having a microprocessor and a network of counters for governing the electrical operation of a fuel control valve of a fuel injection pump. Four subtraction counters are preset by the processor; one is used as a time counter indexed by time pulses and three are used as pump angle counters indexed by pump clock pulses generated for each predetermined increment of pump rotation. Two of the pump angle counters are employed to precisely open and close the valve for regulating the fuel injection timing and quantity--the total quantity in a normal mode of operation and a pilot quantity in a pilot injection mode. In the pilot mode, the third pump angle counter regulates the main injection quantity and the time counter regulates the time delay between the pilot and main injections.