Fuel injection system for internal combustion engine

A fuel injection system for internal combustion engine which comprises in combination:

• a fuel injection valve for supplying fuel to the internal combustion engine;
• air quantity measuring means for measuring a quantity of air passing through an air intake passageway of said internal combustion engine in both forward and backward directions;
• engine-revolution detecting means for detecting number of revolution of said internal combustion engine;
• condition detecting means for detecting each and every condition of said internal combustion engine;
• limiting means which is used when an output therefrom produces a time width of a pulse to be imparted to said fuel injection valve, and which is for limiting a variable related to the atmospheric pressure containing therein at least a quantity of air as measured by said air quantity measuring means with a limited value corresponding to the number of the engine-revolution;
• and atmospheric pressure conformed corrective value computing means, which stores therein reference values for said variables under predetermined atmospheric conditions with at least the number of engine-revolution as a parameter, and which computes the atmospheric pressure conformed corrective value during a predetermined operating condition by introducing thereinto an input signal corresponding to said parameter from said internal combustion engine condition detecting means and an output signal from at least one of said air quantity measuring means and said limiting means, said limiting means correcting said limited value in conformity to the atmospheric pressure by said atmospheric pressure conformed corrective value.