Abstract: A multi-cylinder internal combustion engine is provided with a fuel injection system, which includes a plurality of fuel injection nozzles securely mounted in independent intake passages communicating with combustion chambers of respective cylinders, an air-flow sensor for detecting the amount of intake air to be led into each combustion chamber, a crank angle sensor and a cylinder discrimination sensor for detecting the present stroke timing of each cylinder, a speed sensor for detecting the engine speed and a control unit for outputting a signal to the fuel injection nozzles so that a predetermined amount of fuel may be injected to each cylinder at a predetermined timing on the basis of values detected by the respective sensors. The control unit calculates the injection timing of fuel to be injected into each cylinder so that the injection start timing may be altered in compliance with driving conditions of the engine.

Abstract: A system for controlling the idling speed of an internal combustion engine includes a rotational speed sensor for sensing the rotational speed of an engine, a determination unit for determining whether the engine is in an idling operation state, a memory for storing engine control variables corresponding to the rotational speed of the engine when the determination unit determines that the engine is in the idling operating state, and an engine output controller which, when the discrimination unit determines that the engine is in the idling operating state, reads engine control variable information out of the memory in accordance with the rotational speed sensed by the sensor, and controls the output of the engine in accordance with the information read. Control of engine speed is achieved merely by having the engine output controller read out the engine control variable information from the memory when the engine output is controlled.

Abstract: A system for controlling the operation of an internal combustion engine on the basis of air/fuel ratios and engine loads. A flow rate of intake air sucked into the engine and the cycle of engine revolutions are detected to determine an average flow rate of intake air, which is then used in cooperation with a compression ratio and an engine displacement to determine a net flow rate of intake air or the charging efficiency of the engine. This parameter represents a precise engine load and is used to regulate fuel injected into the engine. As a result, engine operations may be optimally controlled even during transitional operating states of the engine.

Abstract: A novel and improved fuel-injection control system for an internal combustion engine capable of effecting minute or fine revisions of acceleration of an engine by appropriately processing an output signal from an AFS without employing a throttle sensor for detecting the opening degree of a throttle valve. The width of a basic injection pulse is calculated from the amount of intake air sucked into an internal combustion engine and the number of engine revolutions so that between the injection pulses synchronized with the number of engine revolutions, a series of special injection pulses having the calculated pulse width are generated for revision of engine acceleration.

Abstract: The plurality of cylinders of a multicylinder engine are divided into first group cylinders and second group cylinders, and first and second exhaust sensors are provided to respectively detect the air-fuel ratios of the intake mixtures fed to the first group cylinders and second group cylinders. The air-fuel ratio for the first group cylinders is controlled in a closed loop by a first integration signal generated based on the output of the first exhaust sensor and the air-fuel ratio for the second group cylinders is controlled in a closed loop by a second integration signal generated based on the output of the second exhaust sensor. One of the first and second integration signals is corrected so that the air-fuel ratios for the first group cylinders and second group cylinders are increased and reduced in phases reverse to each other.