Self-adjusting fuel injection system

A fuel injection system for a multi-cylinder internal combustion engine including:

• a fuel injection pump including at least one control solenoid, for supplying discrete quantities of fuel to each engine cylinder during each cycle;
• an electronic control system coupled to said solenoid capable of controlling the discrete quantity of fuel injected by controlling the voltage pulse width applied to said solenoid, said control system including a first pulse width generation means, a second pulse width generation means, and an auxiliary memory;
• said auxiliary memory containing sets of numerical data, one set for each engine cylinder, each datum representing an incremental corrective value of the solenoid pulse width for a specific required fuel quantity at specific pump speed, said data entered into said memory during advance testing of the said pump and selected so that at any test point the discrete fuel quantities being supplied to each cylinder are equal to each other and equal to the required fuel quantity;
• said first pulse width generation means providing a first theoretical value of the pulse width determined on the basis of ideal operating conditions;
• said second pulse width generation means providing an incremental corrective value of the pulse width determined on the basis of data selectively read of each engine cylinder and reflecting a correction necessary to compensate for deviation from said ideal conditions, the incremental corrective value being added to or subtracted from the said first pulse width, so that the resulting pulse width is individually tailored for each engine cylinder and the discrete quantities of fuel actually supplied to all engine cylinders at a given engine operating condition are equal to each other and equal to the required fuel quantity;
• said auxiliary memory containing additional data on corrections necessary to compensate for cycle-to-cycle variations in fuel delivery, and said control system using said additional data to make suitable corrections in the solenoid pulse width following a specific sequence corresponding to a known pattern of cyclical variations in fuel delivery;
• and
• a sensor coupled to said control system and the engine capable of recognizing a selected reference cycle and providing a synchronizing signal to said control system to assure that the sequence of corrections is a proper synchronization with the sequence of variations, said additional data being such that said sequence of corrections eliminates cycle-to-cycle variations in fuel delivery.