Abstract: A fuel supply control method for multicylinder internal combustion engines, includes calculating the quantity of fuel being supplied to the engine in response to operating conditions of the engine, and sequentially supplying quantities of fuel corresponding to the calculated values into respective corresponding ones of the cylinders. The fuel quantity is calculated in synchronism with generation of pulses of a timing signal equal in number to the number of the cylinders at predetermined crank angles of the engine per one cycle of the engine.

Abstract: A fuel supply control method for multicylinder internal combustion engines, includes calculating the quantity of fuel being supplied to the engine in response to operating conditions of the engine, and sequentially supplying quantities of fuel corresponding to the calculated values into respective corresponding ones of the cylinders. The fuel quantity is calculated in synchronism with generation of pulses of a timing signal equal in number to the number of the cylinders at predetermined crank angles of the engine per one cycle of the engine.

Abstract: A method of controlling the quantity of supplementary air being supplied to an internal combustion engine having first and second control valves arranged, respectively, in first and second auxiliary air passages bypassing the throttle valve for on-off control of the opening areas of the respective auxiliary air passages. When the engine is operating in a particular operating condition, the first and second control valves are selectively actuated in response to the detected value of atmospheric pressure encompassing the engine in such a manner that the sum of the opening areas of the first and second auxiliary air passages increases as the detected value of the atmospheric pressure decreases. The engine is determined to be operating in the particular operating condition when it is in a cranking condition, when a predetermined period of time has not yet elapsed after the engine has got out of a cranking condition, or when the engine is in a warming-up condition.

Abstract: An air-fuel ratio feedback control system for use with an internal combustion engine, which is adapted to control the air-fuel ratio of a mixture being supplied to the engine, by the use of a first coefficient variable in response to the output of an exhaust gas concentration sensor arranged in the exhaust system of the engine when the engine is operating in an operating condition other than particular operating conditions, and by the use of a second coefficient which is a mean value of values of the first coefficient obtained during the above operating condition other than the particular operating conditions when the engine is operating in one of the particular operating conditions, for replacing the first coefficient with the second coefficient. Storage means is provided for storing and holding the value of the second coefficient even when the engine is inoperative.

Abstract: A fuel supply control method for controlling the quantity of fuel being supplied to an internal combustion engine having a catalytic means for purifying detrimental ingredients in exhaust gases, in a feedback manner responsive to the output of a means for detecting the concentration of an ingredient in the exhaust gases. When the engine is operating in a predetermined high speed operating region wherein the rotational speed of the engine is higher than a predetermined speed, the above feedback control is interrupted and the fuel quantity is increased by a predetermined amount so as to make the air/fuel ratio of a mixture being supplied to the engine richer than a theoretical mixture ratio. Preferably, the above predetermined speed is set at a value which is a maximum value of rpm above which the catalyst bed temperature of the exhaust gas purifying means will exceed a predetermined maximum allowable value, if the air/fuel ratio is controlled to the theoretical mixture ratio or a value close thereto.

Abstract: An abnormality detecting apparatus for detecting abnormality in sensing means for sensing a value of an operating parameter of an internal combustion engine in synchronism with generation of pulses of a signal indicative of predetermined rotational angle positions of said engine. When the sensed value of the operating parameter lies outside a predetermined range, first timer means measures time elapsed from the instant at which the sensed value of the operating parameter falls outside the predetermined range, and decision means decides that the operating parameter sensing means is faulty when the elapsed time measured by the first timer means exceeds a first predetermined period of time.

Abstract: A method of controlling an exhaust gas recirculation quantity in an internal combustion engine. The method is adapted to detect, by means of valve opening detecting means, the actual valve opening of an exhaust gas recirculating valve arranged across an exhaust gas recirculating passageway communicating the exhaust passage of the engine with the intake passage thereof, determine the difference between the detected actual valve opening value and a desired valve opening value calculated in response to operating conditions of the engine, and operate a valve actuator means to close or open the exhaust gas recirculating valve so as to minimize the above difference. When the calculated desired valve opening value exceeds a maximum possible valve opening value, the desired valve opening value is set to the maximum possible valve opening value.

Abstract: An idling speed control method which is adapted to detect by detecting means predetermined rotational angle positions of an internal combustion engine having supplementary air supply control means that regulates the quantity of supplementary air being supplied to the engine, and to control the ratio of operating duty of the supplementary air supply control means to an interval of time at which pulses of a signal indicative of the predetermined rotational angle positions are generated, in a feedback manner responsive to the difference between actual idling engine speed and desired idling speed. When an abnormality is detected in the detecting means, which includes a sensor for sensing the predetermined crank angle positions, a maximum quantity of supplementary air is supplied to the engine by operating the supplementary air quantity control means to its operating limit.

Abstract: A method for controlling the quantity of fuel being supplied to an internal combustion engine having a power transmission means for transmitting engine torque to vehicle wheels. The fuel quantity is controlled to a required value after termination of a fuel cut operation which is effected at deceleration of the engine, by increasing a quantity of fuel set at least as a function of intake pipe pressure by an increment which is set in synchronism with generation of pulses of a predetermined control signal. The increase of the fuel quantity is effected for a period of time after a transition of the operative state of the engine from the fuel cut operation to a normal operation wherein fuel supply is effected has been detected and before a predetermined number of pulses of the above control signal generated are generated, so long as the power transmission means remains in a disengaged state. Preferably, the above increase of the fuel quantity is effected only when the engine speed is lower than predetermined rpm.

Abstract: A method for electronically controlling a fuel injection device which injects fuel into an internal combustion engine, so as to supply a required quantity of fuel to the engine when it is accelerating. It is determined whether or not the engine is operating in a predetermined accelerating condition or in a predetermined decelerating condition, in synchronism with generation of pulses of a control signal having a constant pulse repetition period and being independent of rotation of the engine. When the engine is determined to be in the predetermined accelerating condition, fuel injections are consecutively effected a predetermined number of times in synchronism with generation of pulses of the above control pulse. The above consecutive fuel injections are continued until the above predetermined number of times are reached, so long as the engine is determined not to be in the above predetermined decelerating condition.

Abstract: A fuel supply control method for electronically controlling the air/fuel ratio supply to an engine, in response to the output from means for detecting concentration of an ingredient in exhaust gases from the engine. When the engine is in a feedback control region, the air/fuel ratio control is effected by the use of a first coefficient, the value of which is variable in response to the output from the exhaust gas ingredient concentration detecting means, while simultaneously a mean value of values of the first coefficient applied during the feedback control operation is calculated for use as a second coefficient. The second coefficient and a predetermined value are used for control of the air/fuel ratio, in place of the first coefficient, respectively, when the engine is in a first one of the particular operating regions and when the engine is in a second one of same.

Abstract: A method for controlling the quantity of fuel being supplied to an internal combustion engine having a power transmission means for transmitting engine torque to vehicle wheels. The fuel quantity is controlled to required values after termination of a fuel cut operation which is effected at deceleration of the engine, by the use of increments set in synchronism with generation of pulses of a predetermined control signal. The state of engagement of the power transmission means is detected for a period of time after a transition of the operative state of the engine from the fuel cut operation to a normal operation wherein fuel supply is effected has been detected and before a predetermined number of pulses of the above predetermined control signal are generated.

Abstract: An air/fuel ratio feedback control system adapted to control the air/fuel ratio of an air/fuel mixture being supplied to an internal combustion engine, by the use of a coefficient having a value variable in response to actual exhaust gas concentration. The system is operable to calculate the mean value of values of the aforesaid coefficient for each of a plurality of subregions of the feedback control region when the engine is operating in such subregion. When the engine is operating in one of a plurality of particular operating regions other than the feedback control region, control of the air/fuel ratio is effected by the use of one of such mean values, selected from among the mean values so calculated for each of such particular operating regions, in place of the aforementioned coefficient.

Abstract: A method of controlling a fuel supplying apparatus, particularly, an electronically controlled fuel injecting apparatus is provided, said apparatus having a feedback control function to regulate the air fuel ratio of air-fuel mixture to be supplied to an internal combustion engine on the basis of a fuel amount value representative of a fuel amount to be supplied to the engine, which value is calculated in response to an output signal of an oxygen concentration sensor provided in the exhaust system of the internal combustion engine. The fuel amount value is compared with a predetermined value. When the fuel amount is larger than the predetermined value, the feedback control for the air fuel ratio is stopped, thereby performing the open-loop control for the air fuel ratio, whereby, a simple arithmetic processing is obtained and the arithmetic time is shortened and the memory capacity can be saved.

Abstract: An idling rpm feedback control method for controlling the quantity of supplementary air being supplied to an internal combustion engine, in a feedback manner, responsive to the difference between actual engine rpm and the desired idling rpm. When the engine rpm drops to a predetermined rpm being the upper limit of the desired idling rpm, the above feedback control is initiated. When the engine is decelerated with the throttle valve fully closed, and before the feedback control is started, the supplementary air quantity is controlled in decelerating mode in a predetermined manner while the engine speed drops from a predetermined rpm larger than the upper limit of the desired idling rpm to the same upper limit.

Abstract: An idling rpm feedback control method for controlling control means that controls the quantity of supplementary air being supplied to an internal combustion engine in a feedback manner, in response to the difference between actual engine rpm and desired idling rpm at engine idling, when all predetermined engine operating parameters at least including the throttle valve opening show values satisfying a predetermined condition. When the throttle valve opening detecting means malfunctions, control is effected by maximizing the quantity of supplementary air to the engine by operating the above supplementary air quantity control means to its operating limit.

Abstract: A method for detecting abnormality in parameter sensor means for detecting the value of a parameter relating to the quantity of intake air being supplied to an internal combustion engine for use in control of the operation of the engine. Immediately upon closing of the ignition switch of the engine, an output value from the parameter sensor means is stored. When an output value from the parameter sensor means remains substantially equal to the stored value for a predetermined period of time while simultaneously the rotational speed of the engine remains higher than a predetermined value, the parameter sensor means is regarded as abnormal. Upon determination of occurrence of such abnormality, a predetermined value of the parameter previously stored is used for control of the operation of the engine, in place of an actual output value from the parameter sensor means.

Abstract: An idling rpm control method for feedback control of a control valve for controlling the quantity of supplementary air being supplied to the engine in response to a difference between actual engine idling rpm and desired idling rpm. At the start of the engine, the control valve is continuously opened for a predetermined period of time from the time the engine rpm has increased above a predetermined value lower than the desired idling rpm, thereby maintaining the engine rpm at a value higher than the above desired idling rpm. The above predetermined period of time may desirably be set to a value as a function of engine temperature, preferably detected immediately after the engine rpm has exceeded the above predetermined value of engine rpm.

Abstract: A fuel supply control method for electronically controlling the fuel supply to an internal combustion engine equipped with a supercharger. Pressure in the intake passage downstream of a throttle valve arranged therein is detected by first and second pressure sensor means, whereas a plurality of predetermined values of basic fuel quantity are stored in each of first and second storage means corresponding, respectively, to the first and second pressure sensor means, which are functions of the intake passage pressure and the engine rpm.

Abstract: A method for controlling the fuel injection into an internal combustion engine when it is in a starting condition or in an accelerating condition. When a predetermined control parameter shows a value requiring acceleration of the engine, fuel injections are consecutively effected a predetermined number of times in synchronism with generation of pulses of a control signal having a predetermined constant pulse repetition period and being asynchronous with rotation of the engine, immediately after either generation of a pulse of an engine position signal indicative of a predetermined crank angle of the engine or closing of the ignition switch of the engine has been detected. After completion of the above consecutive fuel injections, fuel injection is suspended until a subsequent pulse of the above engine position signal is generated for the first time after the completion of the consecutive fuel injections.