Abstract: An air-fuel ratio control system for an internal combustion engine having a fuel injection valve for each cylinder and an electronic air control valve (EACV) for controlling intake air bypassing the engine throttle valve. When the target air-fuel ratio is switched over from a rich value to a lean value, the amounts of fuel injected into the cylinders, for example, #1, #2, #3 and #4 cylinders are controlled so that they are sequentially decreased at predetermined intervals, and the EACV is controlled to be opened stepwise. This causes a decrease in engine torque generated by the switching-over of the target air-fuel ratio to be offset by an increase in engine torque generated by an increase in amount of air drawn, thereby preventing the generation of a torque shock. At this time, the target opening degree of the EACV is corrected based on the magnitude of the interval and the magnitude of a loading of the internal combustion engine, thereby further effectively preventing the generation of the torque shock.

Abstract: An apparatus for supplying fuel to an internal combustion engine is disclosed. The apparatus includes an injector that is selectively opened and closed and a pump for discharging the fuel to the injector from a fuel reservoir. The injector is open to inject the fuel to the engine when the engine is running and closed when the engine is idling. The amount of fuel to be injected is adjusted based on the operating state of the engine. A pressure sensor detects an actual pressure of the fuel to be supplied to the injector. A controller computes a target pressure of the fuel to be supplied to the injector. The controller determines a presumed change of engine speed based on the operating state of the engine and controls the pump based on the presumed change.

Abstract: Power to the driven wheels is increased when the motor vehicle is traveling around a curve and the driver suddenly releases the gas pedal. A sudden release of the gas pedal is recognized when the rate of change of pedal position or the engine speed exceeds a threshold on the negative direction, or when the speeds of the driven wheels are less than the speeds of the non-driven wheels.

Abstract: A fuel injection amount in an engine is determined based on a cylinder air volume equivalent fuel injection amount and a wall flow correction amount. The fuel injection amount is also decreased in an initial injection when fuel injection is restarted after it is has been stopped. In this way, sudden torque increases are suppressed without causing a loss of engine rotation speed when fuel injection is restarted after it has been stopped.

Abstract: Electronic system for calculating injection time in which an electronic unit with microprocessor receives as input a multiplicity of signals measured in the engine and a signal proportional to the engine load, for example a signal generated by a pressure sensor arranged in the intake manifold of the engine. The electronic unit comprises a circuit for compensating for the delay times due to the response inertia of the engine load sensor, the conditioning (filtering, conversion and processing) of the load signal and physical actuation of the injection. The electronic unit also comprises a circuit for the dynamic compensation of the "film/fluid" effect.

Abstract: A fuel cut-off operation is delayed until a predetermined delay time period elapses after a fuel cut-off condition is satisfied. During the delay period, the voltage for driving a fuel pump is gradually dropped to decrease the rotation speed of the fuel pump gradually. Thus, the discharge pressure of the fuel pump is low and hence the rise of a fuel pressure immediately after the fuel cut-off operation starts can be prevented. After the fuel cut-off condition, updating of a fuel pressure feedback correction amount is prohibited until the fuel cut-off operation terminates. In this manner, a feedback control immediately after the fuel cut-off operation terminates is executed by using the feedback correction amount used immediately before the fuel cut-off condition to prevent the drop of the fuel pressure immediately after the fuel cut-off operation terminates. Thus, the fuel pressure can be maintained at a target fuel pressure.

Abstract: This invention relates to a wall flow correction of an engine having a fuel injector that injects fuel towards a fuel adhesion part such as an air intake valve. An equilibrium adhesion mount of fuel adhering to a fuel adhering part and a quantity proportion are computed based on a cooling water temperature in a temperature equilibrium state. The adhesion amount of fuel adhering to the fuel adhering part is also predicted at the present time, and the temperature of the fuel adhering part is estimated. A temperature difference between a detected cooling water temperature and estimated fuel adhering part temperature is computed, and an adhesion rate is calculated based on this equilibrium adhesion amount, quantity proportion, predicted adhesion amount and temperature difference. A basic injection amount is corrected using this adhesion rate, and the precision of air-fuel ratio control immediately after start-up when the temperature of the fuel adhering part is in a non-equilibrium state, is improved.

Abstract: In engine idle, a throttle valve is set to an intermediate position between the closed position and the open position, which provides a substantial opening for air flow. When an accelerator is initiated, the sufficient air flow amount and speed are already attained in the engine, the engine rotation quickly increases in response to the accelerator movement. During the period before the accelerator arrives at a pick-up position, an electric control unit controls ignition timing in response to the accelerator movement. The amount of fuel injected to the engine is also controlled depending on the accelerator movement. Also during this period, one or more cylinders are set to be inactive by not supplying the fuel thereto. Thus, the engine rotation speed is controlled to be low at idle.

Abstract: A valve timing control device for an internal combustion engine comprises a variable valve timing mechanism capable of varying a valve overlap period. Fuel injection can be stopped in at least one predetermined engine operating condition and an optimal value of the valve overlap period in the current engine operating condition can be determined, on the basis of current engine speed, load, and temperature. The variable valve timing mechanism can be controlled such that the valve overlap period becomes larger than the optimal value when fuel injection is stopped. Accordingly, in the idle condition when the engine has not warmed up, intake air is heated sufficiently, by the valve overlap period, to more than the optimal value and an engine stall at this time is completely prevented by increasing the amount of intake air.

Abstract: An Electronic Engine Controller (EEC) controls the fuel delivery to an intake of an engine which is equipped with an intake system which includes primary and secondary runners, a primary throttle plate for controlling air flow through both runners and a secondary throttle plate for controlling air flow through the secondary runner. The EEC determines values indicative of the actual and equilibrium amounts of fuel existing in the intake system and controls the fuel delivery based on such values. The actual and equilibrium amounts of fuel include a value indicative of the change in equilibrium fuel due to change in the secondary throttle position.

Abstract: A method and system for generating electronic fuel injection pulse waveforms to achieve an accurate air/fuel ratio control during transient conditions. Sensors are provided for sensing a plurality of engine parameters. An electronic engine controller is provided for performing a plurality of steps associated with the method. The method includes storing calibration data and sensing the engine parameters. A leading edge of the fuel pulse waveform is calculated based on the stored calibration data and the sensed engine parameters. The leading edge of the fuel pulse waveform is generated, thereby triggering an interrupt. Next, a trailing edge of the fuel pulse waveform is calculated based on current fuel mass requirements determined during the duration of the fuel pulse. The method concludes with the step of generating the trailing edge of the fuel pulse waveform.

Abstract: A fuel injection amount control system for an internal combustion engine includes an ECU which calculates a desired amount of fuel to be supplied to each combustion chamber in response to operating conditions of the engine, and calculates values of parameters indicative of fuel adherence characteristics of the interior of the intake passage in response to operating conditions of the engine. The ECU further calculates a first fuel amount which is directly drawn into the combustion chamber from a fuel amount injected by the fuel injection valve, and a second amount of fuel which is carried off the wall surface of the intake passage due to evaporation and drawn into the combustion chamber, based upon the values of the parameters. The ECU calculates an injection amount of fuel to be injected, by correcting the desired fuel amount, based upon the first and second fuel amounts.

Abstract: Timing of delivery of a determined fuel injection quantity is adapted for engine operating conditions including current conditions and likely future conditions under which the fueling requirement may vary significantly from fueling event to fueling event. Parameters are sensed indicating the actual engine operating condition and indicating any current or potential transients, and a fuel injection timing value referenced as a function of the parameters to account not only for the current engine condition, but for likely future conditions.

Abstract: An electronic engine controller (EEC) controls the delivery of fuel to an internal combustion engine via one or more fuel injectors by executing a background routine to measure a plurality of system conditions including airflow and engine temperature. A response value is generated as a function of an aircharge value, the temperature value and a valve effect value. The EEC detects an interrupt which occurs prior to combustion of an air/fuel mixture within each combustion chamber of said engine, and in response to the interrupt execution of the background routine is halted and a foreground routine is executed in which the airflow is measured, an updated aircharge value is generated and the response value is updated as a function of the difference in aircharge values and a predetermined response alteration value. The aircharge value is replaced with the updated aircharge value.

Abstract: A robust engine fueling control is provided for assuring neutral attainment in a vehicular automated mechanical transmission system (10) having a manually controlled master clutch (16). Upon sensing a requirement for a shift into transmission neutral, the disengaging jaw clutch members (134A/142A) are constantly urged into a disengaged position, fuel is caused to decrease to idle (302), and then fuel is blipped by increasingly larger amounts (304, 306, 308) until neutral is sensed.

Abstract: The invention involves stopping the operation of an internal combustion engine, when actual vehicle deceleration is detected after a vehicle deceleration operation. Alternatively, under conditions wherein it is possible to shut off fuel supply at the time of the deceleration operation, the invention involves stopping the operation of the engine by shutting off the fuel supply to some cylinders, and then shutting off the fuel supply to all cylinders when actual vehicle deceleration is detected. Since the fuel supply to the engine is timed to be shut off when the vehicle is decelerated, the speed is reduced smoothly without an accompanying large torque change. Thus, vehicle ride comfort and fuel consumption can be improved.

Abstract: A control system and method for a semi-automatic mechanical transmission system (10) is provided for allowing operator request for a direct downshift or upshift into a preselected start ratio, under certain predefined conditions. The preselected start ratio is that ratio actually utilized in the immediately preceding vehicle start from stop operation.

Abstract: A method of throttle fuel lean-out for an internal combustion engine including the steps of sensing a throttle position of a throttle for the engine with a throttle position sensor, calculating a delta throttle value based on the sensed throttle position, determining whether the engine is in a throttle deceleration condition based on the calculated delta throttle value, linearizing the change in throttle position with respect to absolute throttle position and engine speed if the engine is in a throttle deceleration condition, calculating a throttle deceleration fuel lean-out multiplier value based on the linearized change in throttle position, and applying the calculated throttle deceleration fuel lean-out multiplier value to a fuel pulsewidth value of fuel injectors for the engine and reducing the amount of fuel injected into the engine by the fuel injectors.

Abstract: A control system and method to correct for variations in distillation point of different fuels inducted into an engine (40). Engine rotations or portions thereof are counted until engine start (100-110). A fuel type correction signal is generated from the count (200-212) which then corrects a fuel delivery signal (612-624).

Abstract: A method of load and speed modifying on fuel lean-out for an internal combustion engine includes the steps of sensing a speed of the engine, determining an engine speed modifier as a function of current sensed engine speed, sensing a manifold absolute pressure (MAP) of an intake manifold of the engine, determining an engine load modifier as a function of current sensed MAP, adding the determined engine speed modifier and engine load modifier together to yield a speed/load modifier, and applying the speed/load modifier value to a fuel pulsewidth value of fuel injectors for the engine and reducing the amount of fuel injected into the engine by the fuel injectors.

Abstract: A fuel control system causes a fuel injector to interrupt fuel injection during a continuous decrease in engine speed to a lower limit of a hysteresis range for fuel supply/fuel interruption and to resume the interruption of fuel supply after a continuous increase in engine speed beyond an upper limit of the hysteresis range and further causes a compulsory interruption of fuel supply when a transition of the engine from non-deceleration to deceleration while the engine operates at speeds between the lower and upper limits of the hysteresis range.

Abstract: A method of catalyst purging (run-time) fuel lean-out for an internal combustion engine including the steps of determining whether the engine is in a throttle deceleration condition or a MAP deceleration condition, sensing a speed of the engine, determining whether the current sensed engine speed is above a predetermined speed if the engine is in a throttle or MAP deceleration condition, determining a magnitude of a run-time lean-out multiplier (RTLEAN) value if the current sensed engine speed is above the predetermined speed, and applying the determined RTLEAN value to a fuel pulsewidth value of fuel injectors for the engine and reducing the amount of fuel injected into the engine by the fuel injectors.

Abstract: A control system in an automobile has a controller to provide an air-to-fuel ratio leaner than an ideally combustible air-to-fuel ratio when a lean control range of engine operating conditions is detected, and a controller to increase an air flow rate so as to enrich a fuel mixture when an engine operating condition is transitional to the lean control range. The control system conducts sequentially the lean control and the enrich control according to transitional patterns to the lean control range.

Abstract: A control system for an internal combustion engine estimates an amount of adherent fuel adhering to the inner surface of the intake passage, as well as an amount of carried-off fuel evaporated form fuel adhering to the inner surface of the intake passage and carried into combustion chambers, determines an amount of supply fuel to be supplied to the engine, based upon operating conditions of the engine, the estimated adherent fuel amount, and the estimated carried-off fuel amount, and supplies the determined supply fuel amount into the intake passage. The control system calculates an amount of exhaust gases to be recirculated from the exhaust passage to the intake passage, and corrects the estimated adherent fuel amount and the estimated carried-off fuel amount, based upon the calculated exhaust gas recirculating amount, based upon the calculated exhaust gas recirculating amount.

Abstract: In order to determine the fuel quantity to be fed into an internal combustion engine during each stroke of the engine, the air mass sucked into each cylinder for combustion during each intake stroke is determined based on an intake-pipe pressure. A current air mass is determined using a measured value for the intake-pipe pressure. Subsequently, during a period in which there is no change in an air intake cross-section for each cylinder, the air mass is determined using a projected intake-pipe pressure, and the fuel quantity to be fed to each cylinder during the current and subsequent intake strokes is determined based on the air mass determinations and a wall film model.

Abstract: A fuel supply control system which controls an amount of fuel supplied to an internal combustion engine. An ECU detects a value related to an amount of combustion ions generated within cylinders. The detected value is compared with a predetermined value, and the amount of fuel supplied to the engine is corrected based upon the comparison result, when the engine is in a transient operating condition, such as acceleration and deceleration, whereby the responsiveness of the air-fuel ratio feedback control is enhanced to improve drivability and exhaust emission characteristics.

Abstract: An electronic engine controller (EEC) controls the delivery of fuel to an internal combustion engine via one or more fuel injectors by generating a base fuel value and modifying it with a transient fuel compensation value. The EEC determines the transient fuel compensation value by measuring a temperature value indicative of the temperature of the induction system of the engine and determining a valve effect value indicative of the effect of intake valve temperature on the vaporization of fuel in the induction system. A transient fuel compensation value is then generated in response to the temperature value and the valve effect value. The base fuel value, generated under any of a variety of known engine control methods, including open-loop control and closed-loop control, is altered in response to the transient fuel compensation value to generate a fuel injector control signal for controlling the amount of fuel delivered by the fuel injectors.

Abstract: To determine a correction quantity (KM) of fuel injected in dynamic transition operation, the filter constants (A, B, C) of a filter characteristic are chosen as a function of operating parameters of the internal combustion engine.

Abstract: In a fuel control system of an engine having an air conditioner driven by the engine, fuel supply is cut during deceleration of the engine when the engine speed is higher than a first preset value with the air conditioner on and when the engine speed is higher than a second preset value with the air conditioner off, the first preset value being higher than the second preset value. When the air conditioner is turned off during the deceleration of the engine, fuel supply is cut when the engine speed is higher than the first preset value, and when the air conditioner is turned on during the deceleration of the engine, fuel supply is cut when the engine speed is higher than the second preset value.

Abstract: A correction factor K for the transition correction of the quantity of fuel to be injected on acceleration or deceleration depends upon a pressure change in the intake pipe .DELTA.p which lies in a characteristic field depending on the throttle valve position .alpha. and the rotation speed n.

Abstract: In a fuel injection system for an internal combustion engine, the system calculates the pulse width of the angle-synchronous fuel injection pulses from a main load sensor, such as an inlet manifold pressure sensor (22) or a hot film or hot wire air mass meter (24). Under rapidly-changing load conditions of the engine, the signal from the main load sensor is not sufficiently accurate to maintain a closely stoichiometric mixture. The present invention provides a throttle valve angle sensor for monitoring the degree of opening of an engine throttle (18), and changes the calculation of the basic angle-synchronous fuel injection signal when the measured rate of change of the throttle valve angle reaches a predetermined valve.

Abstract: An electronic control system for fuel metering in an internal combustion engine includes, inter alia, means for determining a basic injection-quantity signal and a transition compensation signal for adapting the quantity of fuel metered-in in the case of acceleration and deceleration, in which, for the purpose of transition compensation, a wall-film quantity signal and a discharge factor signal (Tk) are formed as a function of load and rotational speed, and the transition compensation signal takes into account both the wall-film quantity signal and the discharge factor signal. The discharge factor signal can either be read from a characteristic map or assume two discrete values. The proposed system serves the purpose of achieving a transitional behavior which is as optimum as possible with respect to the exhaust gas.

Abstract: A fuel injection control system for an internal combustion engine wherein the fuel control operates on load range strategies and wherein the amount of fuel is adjusted either by changing the duration or timing of injection during certain transient conditions so as to improve running and prevent stalling.

Abstract: An electronic system for controlling the fuel injection of an internal-combustion engine based on the load, rotational speed, and temperature, as well as at least an oxygen probe reading in the exhaust pipe. The system determines basic injection-quantity signal as well as a transition-compensation signal to adapt the injection fuel quantity in situations of acceleration and deceleration. The system stores an engine characteristics map for a wall-film-quantity signal, and dividing factors for acceleration and deceleration. The system generates a correction value (Wkor) for the wall-film quantity signal and correction factors (FWS1kor, FWS2kor) for the two dividing factors. Three methods are provided for changing the correction factors in connection with the adaptation and these are based on a direct calculation, based on an estimation of the missing quantity and incremental calculation, and based on an incremental adjustment based on the evaluation of the oxygen-probe voltage.

Abstract: An electronic control fuel injection apparatus for a crank chamber compression type 2-cycle engine which compensates a fuel injection amount predetermined by an opening degree of an engine intake air system and an engine speed in response to a fuel amount reduction rate allocated by using a opening degree of the engine intake air system and an engine speed if the engine speed enters an acceleration loss region during a predetermined deceleration and or re-acceleration of the engine while a deceleration of the engine is detected.

Abstract: An air-fuel ratio feedback control method for an internal combustion engine having an exhaust gas ingredient concentration sensor arranged in the exhaust passage and having output characteristics in approximate proportion to the concentration of an ingredient in exhaust gases from the engine, wherein when the engine is in a predetermined operating condition, the air-fuel ratio of an air-fuel mixture supplied to the engine is feedback-controlled to a desired air-fuel ratio dependent on the predetermined operating condition of the engine, and when the engine is in a predetermined deceleration condition, the fuel supply to the engine is cut off.

Abstract: In an automotive power plant including a combustion engine, intake and exhaust passages communicated with a combustion chamber for an introduction of an air-fuel mixture into and a discharge of exhaust gases from the combustion chamber, respectively, a fuel injector for injecting a controlled amount of fuel into the combustion chamber together with air sucked through the intake passage, and a throttle valve of which opening is adjustable for controlling the flow of the air through the intake passage, a fuel control system for determining the amount of fuel to be injected into the combustion chamber in dependence on the amount of air being sucked.

Abstract: An air/fuel ratio control apparatus for a fuel injection type internal combustion engine is able to prevent an air/fuel mixture supplied to the engine from becoming excessively lean even immediately after engine decelerations and thus provide an optimum air/fuel ratio at all times during engine operation. An engine operating parameter sensor such as a pressure sensor, a flow meter, etc., periodically senses an engine operating parameter such as the intake pressure in an intake manifold, the flow rate of intake air sucked into the engine, and the like. A deceleration sensor senses the beginning of engine deceleration. An engine control unit including a microprocessor calculates, from the output signal of the engine operating parameter sensor, a change in the engine operating parameter between two consecutive points in time, and it further calculates a corrected amount of injection fuel supplied to the engine on the basis of the change in the engine operating parameter thus obtained.

Abstract: A fuel control system for an engine has a fuel injector which injects fuel into an intake passage of the engine. An airflow meter detects the amount of intake air of the engine. A controller controls the amount of fuel to be injected from the fuel injection means on the basis of a dulled value by dulling a present value of the output of the airflow meter so that the preceding value of the output of the airflow meter is reflected in the dulled value in a predetermined proportion. The degree of reflection of the preceding value of the output of the airflow meter in the dulled value is reduced when the relation between the value of the output of the airflow meter and the dulled value is inverted.

Abstract: In an internal combustion engine coupled with a supercharger, a basic fuel supply amount is calculated on the basis of an intake air flow rate measured by a hot wire type air flow meter and an engine speed. During an engine decelerating condition, the maximum value (limit value) of the basic fuel supply amount is set on the basis of an open area of an induction system, which is based on a degree of opening of a throttle valve, and the engine speed. The basic fuel supply amount based on the measured value of the air flow meter is limited and can not exceed a value.

Abstract: An engine load parameter-calculating system for an internal combustion engine calculates an engine load parameter indicative of an amount of intake air drawn into the engine. The system determines a value of an opening area formed by a throttle valve and reflecting an amount of intake air, a reference value of the opening area in accordance with the rotational speed of the engine, and a value of the engine load parameter from the value of the opening area and the reference value of same. An engine control system calculates a basic control amount for controlling the engine by the use of the value of the engine load parameter.

Abstract: A fuel control apparatus for an engine which comprises means for measuring an air quantity sucked to the engine and means for supplying fuel to the engine in correspondence with the air quantity sucked to the engine, said means for measuring the air quantity sucked to the engine, measuring n times in one stroke of the engine, said means for supplying fuel to the engine, supplying fuel to the engine of which quantity is based on a ratio of change of the measured value of the air quantity.

Abstract: A fuel control device of an engine which comprises: an intake pipe pressure detecting means; a crank angle signal generating means; a transient state determining means for determining a transient state of an engine; a transient state correction fuel quantity calculating means; an averaging means for averaging the pressure data in a predetermined crank angle signal period; a basic fuel quantity selecting and calculating means for calculating a basic fuel quantity after selecting an output signal of an instantaneous value of the pressure data or an output signal of the averaging means corresponding with an output level of the transient state correction fuel quantity calculating means; a fuel injection quantity determining means for calculating a fuel injection quantity by using the transient state correction fuel quantity and the basic fuel quantity; a fuel quantity measuring means for measuring a fuel quantity for supplying by injection fuel of the fuel injection quantity by the fuel injection quantity determi

Abstract: A system and method for controlling an operation of an internal combustion engine of a vehicle having an automatic transmission in which at least one of predetermined fuel supply recovery engine revolution speed or predetermined fuel supply cut-off engine revolution speed is varied during the engine deceleration condition according to a state of operation of the automatic transmission. In the first preferred embodiment, a downshift operation of the automatic transmission is detected. In the second preferred embodiment, an overrun clutch solenoid is turned on (energized). In the latter case, both fuel supply recovery and fuel supply cut-off engine revolution speeds are set to higher values than those when the clutch solenoid is turned off (deenergized).

Abstract: A fuel injection control apparatus for an internal combustion engine has a controller, which includes a microprocessor for executing a predetermined processing in response to fundamental parameters representing the operational condition of the engine, produces a basic fuel injection pulse on the basis of a suction air quantity and a rotational speed of the engine and corrects the basic fuel injection pulse in accordance with the degree of acceleration or deceleration required, thereby to provide a fuel injection pulse applied to a fuel injector. The microprocessor is provided with membership functions varying with respect to acceleration or deceleration and determines a correction coefficient for correcting the basic fuel injection pulse on the basis of the degree of acceleration or deceleration required in accordance with a fuzzy reasoning using the membership functions.

Abstract: An engine control device for electronically controlling fuel injection of an engine is disclosed. The engine control device includes algorithms for instantaneously calculating fueling requirements in accordance with sensory inputs corresponding to engine operating conditions and throttle position. The fueling requirements are instantaneously reflected as modifications of the duration of fueling signals supplied to the fuel injectors, so that instantaneous fueling changes are effected. Fuel is conserved, and engine responsiveness improved in the current or presently occurring fuel injection cycle as a result of the immediate responsiveness of the engine control device operation.

Abstract: The disclosure describes a method of avoiding an excessive drag torque for motor vehicles. When the accelerator pedal is released, an amount of fuel is supplied to the engine which is approximately under zero-load and which is gradually reduced over time. The occurring change of the rotational speed is monitored. When a certain rotational speed change is exceeded per time unit, the amount of fuel is gradually increased over time until a certain positive rotational speed change is recognized. Then, there is a switch-back to reducing the amount of fuel. The procedure is repeated until the vehicle has reached an operational condition with a constant rotational speed.

Abstract: A fuel injection system for an internal combustion engine of the type wherein the lengths of fuel injection pulses (t.sub.i) are based on engine load signals (TL) developed from a measurement of intake manifold pressure (p) and wherein compensation is provided for the fuel injection signals during transitions between different dynamic operating conditions. Transition compensation for the inlet manifold pressure values representative of engine load is achieved by modifying the pressure values in dependence upon incremental pressure differences (.DELTA.p). The pressure difference values (.DELTA.p) used for this purpose can themselves be modified by other engine-dependent factors (F.sub.1, F.sub.2) when the measured incremental manifold pressure differences (.DELTA.p) exceed predetermined thresholds.

Abstract: An engine control system of a multiple cylinder engine shifts operation between operation with all the cylinders operated and operation with a portion of the cylinders rested under a predetermined condition. When the operation with all the cylinders operated is shifted to operation with the number of the operating cylinders reduced, a control value for controlling the cylinder, such as an amount of fuel to be supplied or an ignition timing, is corrected in a direction of increasing output of the engine, the cylinder being in process of combustion immediately prior to a shift from the operation with all the cylinders operated to the operation with the number of the operating cylinders being reduced.

Abstract: An adaptive control system for categorized engine conditions is disclosed in which the engine conditions to be controlled are discriminated and classified in accordance with the driver's intent and the vehicle operating conditions. It is decided that a given engine control condition is continued or the transition is under way between different control conditions as a history judgement, and a vehicle operation parameter is determined in accordance with the determined history. At the same time, in accordance with the control condition decided and classified, an operating signal is applied to the engine with an operating parameter thus determined and the result of engine control response is observed to update the adaptive parameter.