Abstract: A pedal switch assembly for an automobile is provided with two switch mechanisms so that change-over signals indicative of command to change-over first and second control devices used in the automobile into their selected operational states are produced sequentially as a pedal for operating the automobile is depressed. The pedal switch assembly comprises an actuator operatively associated with the pedal, a first switch mechanism adapted to be operated by the actuator when the amount of pedal depressed exceeds a first set value thereby producing the change-over signal for the first control device, and a second switch mechanism adapted to be operated by the actuator when the amount of pedal depressed exceeds a second set value larger than the first set value thereby producing the change-over signal for the second control device. This enables the change-over control of the individual control devices to be performed at their respective proper timings in operative association with the depression of the pedal.

Abstract: An air-fuel ratio control method which controls the amount of the intake side secondary air in accordance with either the engine temperature or both of the engine temperature and the intake air temperature upon the engine re-start under a high engine temperature, thereby avoiding enrichment of the intake air-fuel ratio even at the occurrence of the percolation phenomenon and to improve the engine-start property. Furthermore, the amount of the intake side secondary air is controlled until the start of the air-fuel ratio feedback control to accomplish improvement in the purification of the exhaust gases and in the stability of the engine speed at an idle state.

Abstract: A method of controlling the air/fuel ratio for an internal combustion engine set a base value of air/fuel ratio control in accordance with detected engine parameters, and the base value is corrected by a base correction value in order to compensate for the error of the base value. The speed of change in the correction value in the learning control operation is increased when the engine speed is low, or for a predetermined time period after a hot starting of the engine.

Abstract: An air intake side secondary air supply system for an internal combustion engine is provided with a linear type solenoid valve disposed in an air intake side secondary air supply passage leading to an intake air passage, downstream from the throttle valve. The opening degree of the linear type solenoid valve is controlled continuously by a drive current supplied to the solenoid. The magnitude of the drive current of the solenoid is determined by providing a base value of current which is responsive to a plurality of engine parameters that represent the engine load, and by correcting the base value in accordance with a result of the sensing of concentration of an exhaust gas component.

Abstract: Air intake side secondary air supply system for an internal combustion engine includes first and second secondary air supply passages leading to an intake manifold in which an open/close valve and an air control valve are respectively provided for a proportional control and an integral control of secondary air. In order to improve a driveability of the engine when no load is applied to the engine when the engine temperature is low, the air control valve is supplied with a pressure for rapidly closing the second air intake side secondary air supply passage so as to stop at least the integral control of the feedback control of air/fuel ratio immediately when a no-load condition is detected during a cold operation of the engine.

Abstract: The so called air intake side secondary air supply system for an internal combustion engine having a choke valve in an intake air passage supplies an air intake side secondary air into the intake air passage so that the air-fuel ratio is feedback controlled. During a period of cold operation of the engine in which the choke valve is actuated to close the intake air passage, the supply of the air intake side secondary air is stopped to enrich the air-fuel ratio upon detection of a no-load operating condition of the engine such as in the case where clutch is disengaged or in the case where the shift position of the transmission is the neutral position or the parking position.

Abstract: A secondary intake air supply system for internal combustion engines having two vacuum operated air control valves in parallel in a single secondary air supply line to the intake manifold. One of the air control valves is controlled by a vacuum control valve to open and close gradually to avoid abrupt changes in the air fuel mixture to the engine, upon changes in vehicle operation. Electromagnetic valves operated by a control circuit responsive to both an exhaust gas sensor and a throttle position also control the secondary air supplied through the two air control valves.