Abstract: In an internal combustion engine with a supercharger, a timing or timings for varying characteristics of kinetic supercharging effects of intake air are synchronized with a timing or timings for varying supercharging pressures by the supercharger. Reduction in engine torque at the time when the supercharging pressure is shifted, can be compensated for by enhancement in the engine torque generated at the time when the characteristics of the kinetic effect are varied.

Abstract: An automobile engine having a device for increasing the inkage air in idle operation when a load is applied to the engine from equipments associate with the engine. An alternator driven by the engine has a voltage regulator which controls the alternator output in response to a load condition on the alternator by controlling the field current. A control unit is provided to restrict an increase in the field current when an electric load is turned on for a time period required for having the engine output increased.

Abstract: A fuel supply control system for an automobile engine which comprises fuel increasing device operable in response to an output fed from an acceleration detector for increasing the quantity of fuel to be supplied, and a rate-of-increase adjusting device for adjusting the rate of increase of the fuel to be supplied. The rate of increase of the fuel to be supplied becomes high as the air-fuel ratio of the combustible air-fuel mixture detected shortly before the acceleration is high.

Abstract: A multiple-displacement engine is provided with a cylinder number control means and a cylinder-reduction determination means in order to switch the operating state of the engine from the full-displacement operation to the part displacement operation or from the latter to the former according to the operating condition of the engine. A period calculating means receives signals generated from a crank angle detecting means every predetermined crank angle and calculates the time interval corresponding to the predetermined crank angle. An engine speed calculating means calculates the engine rpm on the basis of the calculated time interval or period. A crank angle determination means which receives the output from the cylinder-reduction determination means and sets the predetermined crank angle to be submitted to the period calculating means to include a crank angle corresponding to the power stroke of a working cylinder in the part-displacement state of the engine.

Abstract: An engine throttle valve operating device comprising a throttle valve operating foot pedal position detector for detecting the position of the foot pedal and producing a foot pedal position signal corresponding to the position of the foot pedal, a rapid acceleration detector connected with the foot pedal position detection for receiving the foot pedal position signal therefrom and producing a rate signal corresponding to a rate of change per unit time of the position of the foot pedal, a throttle valve actuator for actuating the engine throttle valve, a throttle valve driving signal generating circuit responsive to the foot pedal position signal and the rate signal to produce a first drive signal for operating the actuator in accordance with the foot pedal position signal when the rate of change per unit time of the position of the foot pedal is smaller than a predetermined value and a second drive signal for operating the actuator by a greater extent than under the first drive signal when the rate of change