Abstract: A fuel injection system includes a valve for supplying fuel to an internal combustion engine; a device for measuring the quantity of air passing through an air intake passageway in both forward and backward directions; a device for detecting the number of revolution of the engine; a device for detecting conditions of the engine; a limiting device, which is used when an output therefrom produces a time width of a pulse to be imparted to the fuel injection valve, and which limits variables related to the atmospheric pressure including a measured value of the air quantity limited by the number of engine revolutions; and an atmospheric pressure conformed corrective value computing device.

Abstract: An electronic control system for an internal combustion engine, in which parameters necessary for the engine control are found by use of auxiliary quantities to thereby control the operating characteristic quantities of the internal combustion engine, the electronic control system comprising: a memory device for storing in advance, in the form of a two-dimensional map, a charging efficiency per se or related values of the charging efficiency corresponding to a degree of opening of the throttle valve and a number of engine revolution under the reference atmospheric condition; and a computing device for computing atmospheric pressure related values which include therein at least the atmospheric pressure value and are dependent on the atmospheric pressure, in accordance with a predetermined computation equation which takes a ratio of the charging efficiency per se or related values of the charging efficiency to be found out by selective use of signals of the intake air flow rate and a number of revolution of the

Abstract: An internal combustion engine has an air-fuel ratio control system, an exhaust gas recirculation system and an ignition system. At least one of the systems is adjusted when the intake air temperature is very high so that fast combustion is suppressed. The adjustment is effective to prevent detonation or similar unusual combustion which may occur under a very high temperature of the intake air.