Abstract: An internal combustion engine provided with a system for controlling the predetermined idling rotational speed N.sub.F of the engine, and a system for operating a fuel injector so that the injector is de-energized when the rotational speed is higher than N.sub.cut and the injector is energized when the rotational speed is lower than N.sub.RTN. A value of N.sub.cut is the product of N.sub.F and a predetermined positive value .alpha..sub.1 and the value of N.sub.RTN is the product of N.sub.F and a predetermined positive value .alpha..sub.2 (<.alpha..sub.1).

Abstract: Electric signals produced in association with both a speed of movement of an acceleration pedal and an engine temperature are transmitted to a fuel injection valve in an intake system asynchronously with the running of an engine, so that an amount of fuel being injected from the fuel injection valve is increased as the speed of movement of the acceleration pedal increases and as the engine temperature is lowered. As a result, fuel is injected at a proper rate according to both the acceleration required and the engine temperature, the driving feeling during acceleration as well as a fuel consumption rate are improved, and an amount of detrimental components in the exhaust gases is lowered.

Abstract: The sectional area of an air bypass passage which bypasses a throttle valve in an intake passage of an internal combustion engine is increased or decreased depending upon the difference between the actual rotational speed of the engine and the variable reference rotational speed. The variable reference rotational speed is additionally increased by an incremental value during the starting of the engine.

Abstract: The sectional area of an air bypass passage which is bypassing a throttle valve in an intake passage of an internal combustion engine is increased or decreased depending upon the difference between the actual rotational speed of the engine and the variable desired rotational speed. The variable desired rotational speed is slowly changed with respect to time according to an increment rate or to a decrement rate, when the operating condition of the engine and/or the load condition of the engine changes.

Abstract: The flow rate of intake air sucked into an internal combustion engine when a throttle valve of the engine is at the idling position is controlled so that the actual rotational speed of the engine becomes equal to a desired rotational speed of the engine. This desired rotational speed of the engine is determined by a predetermined calculation, in accordances with the warming-up state of the engine.

Abstract: Ignition timing is controlled in accordance with the engine's operating condition during the time the engine is in a normal operating condition. However, during the starting condition, the ignition timing is fixed to the top dead center in the compression stroke of each cylinder to be ignited.

Abstract: Idle speed of an internal combustion engine is adjusted by applying a drive signal having a predetermined value to a flow rate control mechanism which is disposed in a main bypass passage bypassing a throttle valve while the flow rate control mechanism is energized by the drive signal to operate the engine at close to a desired idling speed, a flow rate adjustment screw in a second bypass passage also bypassing the throttle valve is adjusted to cause the actual speed of the engine to become equal to the desired idle speed.

Abstract: An electronic fuel injection control internal combustion engine which is provided with a feedback control system for maintaining a predetermined constant idling speed and a system for controlling the operation of the fuel injector during the deceleration condition of the engine. A value of the rotational speed when the fuel injector is stopped or recovered is increased during the deceleration condition of the engine.

Abstract: According to the present invention, an amount of fuel being supplied to an internal combustion engine during acceleration is controlled in association with a desired value of acceleration (a degree of acceleration) and a temperature of the engine. The amount of fuel being supplied increases, as the desired value of acceleration is increased, and as the engine temperature becomes lower. Thus, an engine output necessary for rapid acceleration is positively provided, with the assurance of a desirable driving feeling at slow acceleration.

Abstract: The acceleration of an internal combustion engine is detected for generating at least one electrical signal indicating when acceleration exceeds a predetermined degree. In response to this signal, the fuel feeding rate of the engine is instantly increased by a predetermined increment. After each increasing operation is executed, the increased fuel feeding rate is decreased with a variable reduction rate. The variable reduction rate, according to the present invention, is decreased in accordance with the lapse of time after the increasing operation has been executed.

Abstract: An acceleration signal detector is provided for detecting an acceleration condition of an engine based on the open-and-close operation of a throttle valve. Switching arrangements associated with the throttle valve are provided for detecting the fully closed condition of the throttle valve and for detecting a partially closed condition of the throttle valve. Signal processing apparatus receives output signals from the switching arrangements, and a change in the output of the means for detecting a partially closed condition subsequent to a change in the output of the means for detecting the fully closed condition is indicative of acceleration. This arrangement eliminates erroneous signals that might otherwise be caused by chattering of switch contacts.

Abstract: The flow rate of intake air sucked into an internal combustion engine when a throttle valve of the engine is at the idling position is controlled so that the actual rotational speed of the engine becomes equal to a desired value. This desired value of the rotational speed of the engine is adjusted in accordance with the result of a judgement as to whether the actual rotational speed of the engine is increasing or decreasing, and the value of the actual rotational speed of the engine.

Abstract: In conventional electronic fuel injection systems, the flow rate of a fuel supply is fixed during a starting operation irrespective of time variations in the running parameters of an internal combustion engine. In accordance with the disclosed method and apparatus of the invention, however, the fuel supply flow rate is controlled in accordance with the time variations in the engine running parameters in the same manner as occurs after the starting operation, that is, during normal engine running operations, when at least one of the engine operating conditions of r.p.m. being higher than a preset level and flow rate of intake air being higher than a preset level is satisfied. Thus, the engine running operations either at a higher engine r.p.m. or at a higher intake air flow rate during the engine starting period can be stabilized while improving the engine startability and smoothing the engine running operations when an ignition switch is returned from its starting to its "on" position.

Abstract: An apparatus for controlling the amount of secondary air injection including a secondary air injection system which allows the injection of secondary air into an exhaust system for the purpose of causing the combustion of unburned components of the exhaust gas from an internal combustion engine, an air to fuel ratio sensor which determines either the concentration of the oxygen or the concentration of the carbon monoxide in the exhaust gas, a means which senses a sudden acceleration of the internl combustion engine, a control means which sends out an activating signal in response to the output of the air to fuel ratio sensor and the means for detecting a sudden acceleration of the internal combustion engine and a valve means which controls the amount of secondary air injected by the secondary air injection system in response to the activating signal from the control means whereby the valve means causes the amount of secondary air injected into the secondary air injection system to increase when the air to fue

Abstract: In a device for purifying the exhaust gases discharged from an internal combustion engine of the type having a secondary air supply pipe for charging the secondary air from an air source such as an air pump into an exhaust pipe upstream of an exhaust gas reactor or the like, a three-way valve is inserted in the supply pipe in such a manner that the three-way valve may be displaced between a first position at which the air source and the exhaust pipe are communicated with each other and a second position at which the communication between them is interrupted and the secondary air is relieved or returned to the air source bypassing the exhaust pipe; an air-fuel ratio sensor is inserted into the exhaust pipe downstream of the opening of the secondary air supply pipe into the exhaust pipe; and means for controlling the three-way valve is provided so that when the air-fuel ratio detected by the sensor is lower than a reference or optimum ratio at which the best performance of the reactor is expected the three-way

Abstract: An internal combustion engine having an exhaust system provided with exhaust gas purifying means and secondary air supplying means disposed upstream thereof includes a secondary air supply control system comprising vacuum introducing means adapted to introduce and reserve the vacuum from an intake manifold vacuum port; secondary air switching means including two diaphragm means and a valve mechanism linked therewith; information processing means adapted to process the information from an O.sub.2 sensor and an acceleration detector and issue selective commands; and vacuum switching means including two vacuum switching valves to be controlled by the command associated with the O.sub.

Abstract: An internal combustion engine having an exhaust system provided with exhaust gas purifying means and secondary air supplying means disposed upstream thereof includes a secondary air injection compensating system comprising vacuum introducing means adapted to introduce and reserve the vacuum from an intake manifold vacuum port; secondary air switching means including two diaphragm means and a valve mechanism linked therewith; information processing means adapted to process the information from and O.sub.2 sensor and an acceleration detector to make a selection therefrom and issue a command; and vacuum switching means including two vacuum switching valves for selective conduction of said vacuum to said secondary air switching means by said command, and a compensating switching valve.

Abstract: A system for introducing secondary air into an exhaust system of an internal combustion engine of the carburetor type provided with a three-way catalytic converter in the exhaust system is disclosed. The system includes a flow control valve which has a valve member operated by a vacuum signal in the engine intake system for controlling the amount of secondary air flowing into the engine in accordance with electric signals sent from a .lambda.-sensor which is arranged in an exhaust system of the engine so that the excess air ratio .lambda. of the exhaust gas introduced into the three-way catalytic converter is controlled near 1.0, which is a suitable ratio for the operation of the three-way catalytic converter. The system further includes means for operating the valve member quickly so that the excess air ratio .lambda. is rapidly controlled near 1.0; therefore, an effective cleaning operation of the three-way catalytic converter is expected.

Abstract: An apparatus for introducing secondary air into an exhaust system of an internal combustion engine, provided with a three-way catalytic converter in the exhaust system. The apparatus includes a first air flow control valve adapted for controlling the amount of air introduced into the exhaust system in accordance with the atmosphere of the exhaust gas so as to cause it to be kept near stoichiometric atmosphere, and a second air flow control valve adapted for preliminarily controlling the amount of secondary air introduced into said first air flow control valve in accordance with the amount of engine fluid passing through the intake system or exhaust system. The atmosphere control operation by the first air flow control valve is effectively promoted by the second air flow control valve, so that atmosphere of the exhaust gas can be strictly and precisely controlled to said stoichiometric atmosphere for proper operation of the three-way catalytic converter.

Abstract: Disclosed is an apparatus for introducing secondary air into an exhaust system of an internal combustion engine, provided with a three-way catalytic converter in the exhaust system. The apparatus includes a flow control valve adapted for controlling the amount of air introduced into the exhaust system in accordance with the atmosphere of the exhaust gas so as to cause it to be kept near a stoichiometric atmosphere, and a pressure control valve adapted for keeping a predetermined constant pressure difference of the secondary air between a position upstream from the flow control valve and a position downstream from the flow control valve. The atmosphere control operation by the flow control valve is effectively promoted by the pressure control valve, so that atmosphere of the exhaust gas can be strictly and precisely controlled to said stoichiometric atmosphere for proper operation of the three-way catalytic converter.