Abstract: An electronic digital control system monitors and controls the operation of an engine fueling system. Signals activating injection for a plurality of cylinders are transmitted through a single line to a driving circuit for a single injector solenoid valve, while signals controlling accumulator fuel pumps are transmitted to pumping control solenoids. Injection signals are controlled to vary fuel delivery rate during an injection event. A back EMF sensing circuit measures valve opening delay and the control system compensates for valve delay. Variable cylinder-specific delays in the injection solenoid output signal pulses are programmed to compensate for a varying fuel line length to each injector nozzle. At startup, the control system pulses the pumping control solenoids to begin pressurizing the accumulator before engine angular position sensors provide an accurate indication of engine angular position to allow precise timed control of the pump.