Fuel injection system for an internal combustion engine

A fuel injection system for an internal combustion multi-cylinder engine comprising:

• fuel injection means for injecting fuel under a predetermined pressure into each of a plurality of cylinders in said engine;
• an air-flow sensor arranged in the suction duct of said engine for generating a first electrical signal corresponding to the quantity of air drawn into said engine;
• a reference signal generating means adapted to be connected to the crankshaft of said engine and having a rotor associated with said crankshaft and provided with as many equispaced means thereon as the number of said cylinders, a pair of detecting means arranged to generate a pair of signals upon engagement with said equispaced means in less than 720.degree./(2 .times. the number of cylinders) of rotation of the crank shaft, and a flip-flop connected to said detecting means for generating a second electrical signal having a time width equal to the internal between said pair of signals;
• main computing means connected to said air-flow sensor and said reference signal generating means for repeating, in accordance with said first and second electrical signals, the charging and discharging of electrical energy, said charging being completed during said time width of said second electrical signal, said discharging beginning after completion of said charging, said main computing means generating, during the discharging, a third electrical signal for controlling the operating time and the operating time duration of said fuel injection means;
• and
• distributing means connected between said main computing means and said fuel injection means for separately distributing said third electrical signal to said fuel injection means in accordance with the firing order of said engine.