Abstract: An exhaust gas purifier equipped with a catalyst converter including an early-activation catalyst converter and a pre-catalyst converter for purifying harmful exhaust gas discharged form an engine evaluates a characteristic of the exhaust gas purification rate of the catalyst converter from the cooled condition to the warmed condition of a catalyst to diagnose a deterioration of the early-activation function of the catalytic converter.

Abstract: An internal combustion engine control device having exhaust gas sensors provided before and after a catalyst or after the catalyst, a processor for signals from the exhaust gas sensors, and an electronic controller. The electronic control is arranged for controlling the amount of fuel to be fed to the internal combustion engine, ignition timing, the amount of secondary air for reducing the emission, the amount of EGR (exhaust gas recirculation), electrically heated catalyst, assisted air flow, and gas flow in the cylinders or intake exhaust valve timing of internal combustion engine. Using the controller the conversion rate (degree of activation) is detected with high precision from the processed sensor signals, and the emission is most suitably controlled to be reduce according to the degree of activation in order to meet both present stringent exhaust gas regulations and those which are predicted for the future.

Abstract: A method and apparatus for monitoring deterioration of an internal combustion engine exhaust gas purifier in which first and second sensors are disposed on the upstream and downstream sides respectively of the purifier. The sensors are connected to an electronic control unit which, in normal operation, is arranged to control the air-fuel mixture supplied to each cylinder of the engine by controlling the amount of fuel supplied by an injector so that the air-fuel ratio is a predetermined mean value. The air-fuel ratio is changed from one predetermined value to another predetermined value and delay time taken for the second sensor to change its response subsequent to said change is indicative of the condition of the purifier so that deterioration of the purifier may be readily determined.

Abstract: In an air-fuel ratio control method and apparatus for an internal combustion engine supplied with a gas mixture of air and fuel, in which an actual air-fuel ratio is determined from exhaust gas components by using an O.sub.2 -sensor installed in an exhaust pipe of the engine, and the air-fuel ratio of the mixture gas to be supplied to the engine is controlled through feedback control on the basis of deviation of the actually detected air-fuel ratio from a reference value (A/F=14.7). Performance of the O.sub.2 -sensor is determined by making use of change in the air-fuel ratio output of the O.sub.2 -sensor at a time of interruption of the fuel supply to the engine or at a time the fuel supply to the engine is restarted.

Abstract: A combustion fault detection apparatus for an internal combustion engine, in which a cylinder signal is generated when the piston in each cylinder of the engine is located at a predetermined position, a time interval between cylinder signal is determined, and time intervals for respective cylinders are compared and computed thereby to detect when a combustion fault, if any, has occurred in a specific cylinder.

Abstract: An estimating execution for an inner surface portion adhesion fuel amount is practiced distinctlly and independently to an execution processing for a basic fuel injection amount. A correction coefficient to be multiplied by the basic fuel injection amount is calculated in accordance with the estimation execution for the inner wall surface portion adhesion fuel amount. The correction coefficient is multiplied by the basic fuel injection amount. Since the fuel injection amount is corrected in accordance with the estimated inner surface portion adhesion fuel amount, an air-fuel ratio during a transitional period of an engine can be maintained at a desirable value.

Abstract: A control unit has a fuel supply controller and a throttle valve opening degree controller. The fuel supply amount controller estimates and calculates the amount of fuel being supplied in cylinders with a real time. The throttle valve opening degree controller calculates a necessary opening degree so as to give a predetermined air-fuel ratio in accordance with a result value by the fuel supply amount controller. The fuel supply amount controller has a processing in which a fuel supply amount is corrected in accordance with an increase or decrease rate of an amount of fuel being adhered to an inner wall surface of an intake pipe. The throttle valve opening degree is controlled in accordance with a value obtained from the throttle valve opening degree controller as a control target value. A time lag in a follow-up for fuel is anticipated in advance, a desirable target air-fuel ratio is maintained correctly and easily.

Abstract: A control unit outputs a data through an execution of each frequency of an engine driving operation condition such as an operation amount of an accelerator pedal, an engine speed, and a gear position. Frequency distribution of the engine driving condition is made through an addition processing and a subtraction processing in an area division. The present target throttle opening degree is determined through an area division judgment in the control unit. An actual throttle opening degree is adjusted so as to become a target throttle opening degree. The target throttle opening degree is searched through a map for searching the target throttle opening degree. The obtained engine control conditions are stored and memorized successively in the control unit, and an engine control characteristic is selected in sequence according to the memorized results. An operation characteristic corresponding to the driver's driving operation is selected and an optimum operability performance is obtained.

Abstract: In an engine control apparatus for controlling the amount of fuel to be supplied by calculating the amount of liquid film or fuel adhered to an intake pipe of an engine, the adhesion rate of fuel and the time constant of evaporation of fuel in a preestimating manner, the time constant of evaporation is determined on the basis of the determined amount of liquid film, the amount of suction air and an air-to-fuel ratio upon fuel cut and the adhesion rate is determined on the basis of the amount of supply of fuel, the amount of suction air and an air-to-fuel ratio upon fuel recovery.

Abstract: An internal combustion engine control apparatus in which upon detection of transient state of the engine such as acceleration, deceleration or the like, the amount of fuel supply to the engine is corrected by using transient correcting coefficients which are determined previously and updated through learning procedure. The correcting coefficient is updated on the basis of the result of comparison of the air-fuel ratio detected upon occurrance of the transient state with a predetermined reference value.

Abstract: A fuel adhesion percentage of an injected fuel to a surrounding portion of an intake valve is determined in accordance with a fluctuation value of an air-fuel ratio correction coefficient and a fluctuation value of a signal of an air-fuel ratio detecting sensor or a signal of an oxygen amount detecting sensor. Each adhesion percentage of the injected fuel is divided and stored in each division area of a characteristic memory map of a control unit. The adhesion percentage of the injected fuel is stored in a memory of the control unit and is determined in accordance with present throttle valve opening degree and present engine coolant temperature by the characteristic memory map. The adhesion percentage of the injected fuel is obtained through a learning control process in the control unit. An air-fuel ratio correction in a transient period is carried out smoothly.

Abstract: Values of a correction amount of correcting a fundamental control amount of an internal combustion engine are stored in a rewritable memory having divisional storage areas corresponding to divisional running areas. When a value of the correction amount for a particular divisional running area is renewed, concurrently therewith, values of the correction amount for divisional running areas adjacent to the particular divisional running area are also renewed.

Abstract: A fuel injection system of the type in which the opening time of a fuel injection valve is controlled on the basis of a predetermined program and in accordance with various operation parameters such as the intake air flow rate, engine speed and engine temperature. The system has a means for detecting at least one of the offset of the engine speed from a command speed and the engine speed variation per unit time, the data being used together with the above-mentioned operation parameters in controlling the opening time of the fuel injection valve.

Abstract: The ignition timing is controlled in that a change in engine speed is detected from a differentiated value dN/dt, and when dN/dt is larger than a predetermined value and when a value of dN/dt is positive, the ignition timing is retarded by a predetermined value from a fundamental ignition timing, and further, when dN/dt is larger than the predetermined value and when the value of dN/dt is negative, the ignition timing is advanced by the predetermined value from the fundamental ignition timing.

Abstract: An apparatus for controlling the idling engine speed of an automobile engine comprises: an engine speed sensor for detecting an engine speed; a control unit for calculating a difference between an actual engine speed detected by the sensor and a targeted idling engine speed preset in accordance with the operating conditions of the engine, for judging whether or not a power steering system is being operated to a point close to an operatable limit thereof when the automobile is at a standstill, and for outputting a signal for increasing by a predetermined value a gain of a proportional term for proportional-integral type feedback control employed in controlling the idling engine speed if judgment is made that the power steering system is being operated to a point close to the operatable limit thereof when the automobile is at a standstill; and an ISC valve for adjusting a flow rate of air supplied to the engine in accordance with a signal output by the control unit.

Abstract: A tubular trembler supported on an ultrasonic vibrator is disposed almost on an axis in an engine intake pipe and has a fuel passing-through hole in the wall thereof. A fuel jet tip of the electromagnetic injection valve is disposed so as to face the fuel passing-through hole so as to jet the fuel divergently against an inside wall of the tubular trembler through the fuel passing-through hole. The fuel is injected against the inside wall of the trembler through the fuel passing-through hole and is atomized. When the fuel is jetted into the fuel passing-through hole from the fuel jet tip, the relative distance from the fuel jet tip to the inside edge of the fuel passing-through hole is determined so that most of the injected fuel will strike the inner wall of the tubular trembler, within the dimensions determined by the bore, the fuel passing-through hole, the inside diameter and the length of the tubular trembler and the angle of the spread of the injected fuel.

Abstract: There is disclosed an electronic control system for controlling a carburetor equipped with a slow-main system solenoid valve and an enrichment system solenoid valve of different control ranges whose openings are electromagnetically controlled to control the air-fuel ratio of a mixture supplied to an internal combustion engine. The control system calculates, based on signals representative of the engine operating condition including engine temperature, the duty for control of the slow-main system solenoid valve in accordance with the air-fuel ratio required for various engine operating states. When the value of this duty exceeds a predetermined value, the enrichment system solenoid valve is added to the slow-main system solenoid valve to accurately control the air-fuel ratio over a wide range.

Abstract: An engine revolution speed control device includes sensors (8, 9, 10) for detecting parameters representing the engine conditions, an actuator (7) for controlling the reset position of the throttle (13), a switch (11) producing a signal when the throttle action returns under the control of the actuator (7) and a device (12) which is cyclically driven under the condition that no signal from the switch (11) exits. The device (12) takes in one of the data from the sensors (8, 9, 10) and operates the actuator (7) by a predetermined amount in such a direction as to close the reset opening of the throttle every time that the amount of variation in the data taken in reaches a predetermined value.

Abstract: In an apparatus for controlling an internal combustion engine in which the quantity of air supplied to the engine is controlled to control the warming-up rotational speed of the engine, a first desired warming-up rotational speed characteritic relative to the temperature of engine cooling water and a second desired warming-up rotational speed characteristic lower in rotational speed level than the former are stored in an ROM of a micro-computer, so that, when the throttle valve is not opened during warming-up of the engine, the actual rotational speed of the engine coincides with the first desired warming-up rotational speed, while, when the throttle valve is opened during warming-up, the actual rotational speed of the engine coincides with the second desired warming-up rotational speed.

Abstract: In a single point electronic fuel injection system for injecting fuel at the upstream side of a throttle valve in synchronism with the sucking stroke of engine, upon low-speed driving, particularly upon idling drive, the total amounts of fuel necessary for a previous sucking stroke and the following sucking stroke are injected at a time in the previous sucking stroke and no fuel is injected in the following sucking stroke.