Abstract: In a fuel control apparatus by which a basic fuel quantity T.sub.p is first calculated on the basis of a detected intake air flow rate Q and a detected engine speed N as T.sub.p =KQ/N (K: constant) and the calculated basic fuel quantity T.sub.p is corrected on the basis of a correction coefficient COEF related to various engine operating conditions (e.g. coolant temperature), air/fuel ratio feedback correction coefficient .alpha., and a battery voltage correction coefficient T.sub.s as T.sub.i =T.sub.p .times.COEF.times..alpha.+T.sub.s, when an engine is accelerated, an initial fuel increment coefficient KAC.sub.0 is determined on the basis of throttle opening rate and engine speed, and added to the correction coefficient as COEF+KAC.sub.0, and thereafter the initial fuel increment coefficient KAC.sub.0 is reduced at a small coefficient decrement rate DKAC.sub.1 at lower engine speed to prevent hesitation, but at a large coefficient decrement rate DKAC.sub.

Abstract: An electronically-controlled fuel injection system having a synchronous counter which receives main injection time data corresponding to an amount of fuel to be injected synchronously to engine revolutions, and an asynchronous counter which receives increment injection time data corresponding to an amount of fuel to be injected at a selected time interval asynchronously to the engine revolutions, wherein the synchronous counter is operated for a period of time equal to the main injection time data upon receiving a synchronous signal which is generated synchronously to the engine revolutions, while the asynchronous counter is operated for a period of time equal to the increment injection time data upon receiving an asynchronous signal which is generated at the selected time interval, so as to open a fuel injection valve by pulses which are output from the respective counters during the operations thereof.

Abstract: An air fuel ratio control apparatus, performs fuel decrease compensation during deceleration with respect to an air fuel ratio upon detection of a returning operation of a throttle valve. To avoid variations in torque which detract from a smooth ride, fuel decrease compensation is prohibited under the conditions that the opening of the throttle valve is in a full opening region and the amount of return movement of the throttle valve per unit time is equal to or less than a preset valve.

Abstract: A method of and apparatus for controlling a fuel injection quantity for an internal combustion engine wherein the fuel injection quantity is controlled on the basis of both an intake-pipe pressure and a rotational speed of the engine. The output of a pressure sensor for detecting the intake-pipe pressure is processed by a CR filter having a time constant which enables removal of a pulsating component of the intake-pipe pressure. The output of the CR filter is relaxed to calculate a first weighted mean value with a relatively low degree of relaxation and a second weighted mean value with a relatively high degree of relaxation. The second weighted mean value is subtracted from the first weighted mean value, and an incremental/decremental quantity is determined on the basis of the result of the subtraction.

Abstract: An apparatus for learning and controlling an air/fuel ratio in an engine wherein a fuel injection quantity Ti is computed by correcting a basic fuel injection quantity Tp by a feedback correction coefficient LAMBDA based on a detected air/fuel ratio. Deviation of LAMBDA from a reference value during the feedback control is learned to determine a learning correction coefficient, and on computation of Ti, Tp is corrected by a learning correction coefficient. A base air/fuel ratio obtained from Ti computed without correction by LAMBDA is made in agreement with an aimed air/fuel ratio and during the feedback control, Ti is computed by further correcting the air/fuel ratio by LAMBDA. The learning correction coefficient is divided into an altitude learning correction coefficient K.sub.ALT for learning deviation by the change of the air density with respect to all the areas of the engine driving state and an area-wise learning correction coefficient K.sub.

Abstract: A fuel injection control system for controlling the amount of fuel to be injected to an internal combustion engine. The fuel injection control system consists of a control unit arranged to calculate the fuel injection amount in accordance with a standard injection amount corrected with a transient correction amount. The transient correction amount is calculated in accordance with a difference value and a correction coefficient which is previously set in accordance with engine operating condition. The difference value is of between an equilibrium amount of adhering and floating fuel in steady state in an intake system and a predicted variable of amount of the adhering and floating fuel at a predetermined point of time.

Abstract: The engine idling speed control system in an internal combustion engine for a vehicle provided with an automatic transmission device. A shift down operation induced for attaining an engine braking effect is detected, and upon detection of such a shift down operation, the idling speed control system is controlled so that the intake air amount is incremented. As a result, an increase in an engine torque is obtained for decreasing shock during a shift down operation executed in an automatic transmission.

Abstract: A novel method of controlling air-fuel ratio for an internal combustion engine is disclosed, which comprises a memory area for holding regional compensation factors used for air-fuel ratio control, a memory area for holding new regional compensation factors obtained by learning, and a memory area for holding regional compensation factors based on the result of the learning immediately before the latest learning, thus rationalizing the new setting and updating proceses of regional compensation factors according to the result of learning.

Abstract: An adaptive charge mixture control for an internal combustion engine includes four input signals supplied to an OR gate to generate a net "go rich" signal supplied to a servo motor controlling an air/fuel charge mixture control valve for an internal combustion engine. The servo is also supplied with a "go lean" fixed signal tending to lean out the air/fuel mixture. The four "go rich" signals include a first signal derived from a comparison of engine speed with a predetermined minimum (i.e., idle) level; a second signal derived from comparing throttle positions with a preset minimum throttle position; a third signal derived from comparing engine deceleration rate with a preset engine deceleration rate; and a fourth signal derived from a measurement of engine instantaneous power output.

Abstract: A fuel injection control system performs fuel injection for each engine cylinder at mutually different timings in each engine revolution cycle. First and former fuel injection is take place at a timing well advanced in view of a timing of opening of an intake valve of the corresponding engine cylinder to inject full amount of fuel derived on the basis of an engine load and engine speed. Second fuel injection is performed at a timing close to or within the intake valve open period for injecting an amount for compensating fuel amount to be increased depending upon increase of the engine load. In addition, acceleration enrichment upon engine acceleration demand is taken place by adjusting the fuel injection amount for second fuel injection.

Abstract: A system for cutting off the supply of fuel to an automobile engine in a specific operating region within the deceleration region of the engine determines whether the engine transmission is manual or automatic. The system has for each of the manual transmission and automatic transmission, a fuel cut-off rpm at which the supply of fuel is cut off when sensed engine rpm is greater than the fuel cut-off rpm, and a fuel restoration rpm, which is set to be less than the fuel cut-off rpm, at which the fuel supply is resumed when sensed engine rpm is less than the fuel restoration rpm.

Abstract: A fuel supply control apparatus for an internal combustion engine comprises a detecting means for detecting the decrement of air intake quantity for the internal combustion engine and a sensor for detecting temperature of the cooling water of the internal combustion engine so that the fuel supply quantity is decreased according to the temperature of cooling water when the decrement of air intake quantity is detected, thereby enabling rapid decrement of fuel supply quantity according to the decrement of the revolution of the engine and compensation of fuel supply loss, which is caused by adhesion of liquefying fuel inside the air intake pipe and the like, according to the temperature of cooling water.

Abstract: A basic fuel injection time is obtained based on engine speed and intake-air pressure in an intake passage of an engine downstream of a throttle valve of the engine. The basic fuel injection time is corrected by a correcting value based on a constant for a fuel injector and capacity of a chamber formed in an intake passage and on variation in intake-air pressure at every one rotation of a crankshaft of the engine when the idling state of the engine or throttle rapid closing are detected.

Abstract: In a fuel injection system with an acceleration enrichment and a deceleration leaning, in which the transition compensation is determined by means of the throttle valve change speed in connection with the throttle valve change path. By means of the measurement of the throttle valve position the cause for the change of the air quantity is determined so that the information concerning a change of the operating state is present more quickly and a fuel leaning or fuel enrichment can accordingly also be effected more quickly. An intermediate injection threshold, which activates an intermediate injection calculation when exceeded, is built in, in addition, for the acceleration enrichment.

Abstract: In a control system for an internal combustion engine, in which the amount of fuel is determined on the basis of the depression amount of an accelerator pedal and the amount of air is determined on the basis of the fuel amount, the changing amounts of the fuel and air are corrected by the changing rate of the accelerator pedal depression amount.

Abstract: The invention is directed to a method for the adaptation of mixture control for an internal combustion engine which is set up from operating quantities of the engine such as throttle flap angular position .alpha. and rotational speed n. The characteristic field provides a precontrol quantity governing the quantity of fuel to be metered or injected. The method includes the steps of: influencing the precontrol quantity by at least one adaptively changeable corrective quantity (structural adaptation, global adaptation); detecting the negative change velocity (-d.alpha./dt) of the throttle flap position angle (.alpha.); comparing the negative change velocity (-d.alpha./dt) with a predetermined threshold value [-d.alpha./dt(SchAd)]; evaluating a quantity (.DELTA..alpha.) indicative of the throttle flap change in angular position when the threshold value [-d.alpha./dt(SchAd)] is exceeded, the quantity (.DELTA..alpha.

Abstract: An arrangement for an internal-combustion engine having at least two intake valves for achieving a more abundant course of the torque in the partial-load operation and a high output in the full-load operation, is equipped with separate intake pipes that are dimensioned differently with respect to their length and/or their diameter and separately lead to the intake valves. The shorter intake pipe is closable by a flap. Each intake pipe is equipped with a separate fuel injection valve. A total fuel quantity that is determined by an injection control computer, during the opening and closing of the flap, corresponding to the flow conditions that change in the intake pipes, is apportioned to the two intake pipes via the injection valves. As a result, in addition to the favorable operating behavior of the internal-combustion engine, in the whole torque and load range, an optimal apportioning and formation of the mixture is achieved, even during the opening and closing of the flap.

Abstract: In an electronic fuel injection control device for an internal combustion engine, an A-D converter is provided to convert an analogue signal indicative of a physical value such as an intake manifold negative pressure or an amount of suction air to a digital value, and a computer is programmed to calculate an average of a plurality of the digital values successively converted during one rotation of the engine, to determine whether or not a difference between the preceding average of the digital signals and the following average of the digital signals is larger than a predetermined value indicative of a transient operation of the engine, if so determine a first optimum physical value based on an average of at least two digital values most newly converted during one rotation of the engine, and if not determine a second optimum physical value based on the average of the digital values, and to determine an optimum fuel injection time based on one of the first and second optimum physical values and in relation to r

Abstract: In a double air-fuel sensor system including two air-fuel ratio sensors upstream and downstream of a catalyst converter provided in an exhaust gas passage, an actual air-fuel ratio is adjusted in accordance with the outputs of the upstream-side air-fuel ratio sensor and the downstream-side air-fuel ratio sensor. The adjustment of the air-fuel ratio by the downstream-side air-fuel ratio sensor is stopped when the engine is in a predetermined state.

Abstract: A method of engine air/fuel ratio control whereby a compensation value is computed for compensating an error of a basic fuel injection time interval. The computation is periodically performed as an operating sequence including steps of computing a current first compensation value, utilizing a preceding first compensation value (obtained and memorized during a previous execution of the sequence, under the same engine operating conditions as those of the current first computation value), obtaining a second compensation value based on the deviation between a detected air/fuel ratio and a target air/fuel ratio, and compensating the basic value by the first and second compensation values to obtain an output value, used to control fuel supply to the engine. In addition, while engine acceleration or deceleration is occurring, the basic value is corrected by a transition compensation value, computed in accordance with the degree of acceleration or deceleration.

Abstract: A fuel injection system for an internal combustion engine comprises a fuel injecting valve, L-jetronic calculating means for calculating the amount of fuel to be injected based upon the output from an air flow meter under an engine operating condition where the amount of intake air is small, D-jetronic calculating means for calculating the amount of fuel to be injected based upon outputs from engine load detecting means and engine rpm detecting means under an engine operating condition where the amount of intake air is large and correcting means for correcting the amount of fuel to be injected upon switchover between the L-jetronic and D-jetronic calculating means in response to engine operating condition changes. As a result, the difference between successive amounts of fuel to be injected is never large. of fuel injected lastly.

Abstract: An engine having a fuel injector for normally feeding a lean air-fuel mixture into the engine cylinders. Ignition timing is determined so that it is suitable for the lean air-fuel mixture. The gear changing operation of the transmission of the engine is detected from the change in the engine speed and the change in the absolute pressure in the intake passage. When the gear changing operation is carried out, a rich air-fuel mixture is fed into the engine cylinders, and the ignition timing is retarded.

Abstract: A fuel supply control system for use in an engine includes a feeder for supplying fuel to the engine in an amount suitable for operating conditions of the engine, a detector for detecting a decelerating state of the engine, and a correcting device for, upon detecting the deceleration, increasing a rate of fuel supply so that combustion may be stabilized to prevent car-bucking. The system further includes a brake detector for detecting an operative state of a brake device of the vehicle, and a limiter for, upon operation of the brake device, limiting the increase of fuel supply whereby the fuel consumption efficiency can be improved. During operation of the break device, car-bucking is restricted by a braking force so that substantially no vibration is transmitted to a driver.

Abstract: The fuel supply to an internal combustion engine is decreased when the engine is in an operating region wherein the intake passage pressure is lower than a first predetermined value. The first predetermined value is corrected in response to detected atmospheric pressure encompassing the engine. Further, the fuel supply to the engine is interrupted when the engine is in a second operating region wherein the intake passage pressure is lower than a second predetermined value, which is lower than the first predetermined value. The second predetermined value is corrected in response to the detected atmospheric pressure, together with the first predetermined value.

Abstract: An air/fuel ratio control system for an internal combustion engine includes an oxygen concentration sensor for sensing the oxygen concentration in the exhaust gas of the engine, and a correction value setting device which determines a correction value corresponding to an output signal of the oxygen concentration sensor obtained when the fuel cut operation of the engine has continued for more than a predetermined time period. The output signal of the oxygen concentration sensor is corrected by the correction value during the engine operation other than the fuel cut operation.

Abstract: In a fuel injection controlling method for an internal combustion engine having the hot were air flow meter and the valve opening pulse generating means for a fuel increment independently of the basic valve opening pulse generating means for causing the injector to inject fuel normally during the normal condition, the valve opening pulse for a fuel increment has a duration dependent on at least one of selected from variations in the air intake volume per unit time, a closing signal of the idle switch for the throttle valve, a signal indicating the number of revolutions of the engine, etc., independently of the duration of the basic valve opening pulse. The acceleration adjustment is adjusted the fuel increment in accordance with the valve opening pulse for a fuel increment. It is possible to obtain optimum acceleration by varying the adjustment depending on conditions for interrupt adjustment during acceleration.

Abstract: An engine control system includes a stall-preventive feature in which prevailing engine conditions are checked against patterns known to lead to engine stall. A number of crucial engine parameters and continuously monitored, as are one or a number of subsidiary conditions, such as air conditioner operation and transmission position, which may significantly increase the probability of engine stall under certain, known conditions. When these known conditions are detected, engine parameters are sampled at regular intervals for a predetermined period of time to derive a number of parameter variation curves or patterns which can then be compared to similarly-derived empirical patterns which are known to lead directly to engine stall. When the current and predetermined patterns match or closely correlate, the engine control system is signalled to perform a stall-preventive operation. The stall-preventive operation consists of steps serving to increase engine output torque, decrease the load on the engine or both.

Abstract: This invention relates to a control system for feedback control of the air/fuel ratio in an internal combustion engine, which may be an automotive engine, by using an oxygen sensor to detect actual values of the air/fuel ratio from the concentrations of oxygen in the exhaust gas. The control system has the function of temporarily shifting the feedback control of air/fuel ratio to open-loop control when any of predetermined transient operating conditions of the engine is detected. To resume the temporarily interrupted feedback control at an optimum time-point, the air/fuel ratio control system includes means to detect the degree of warm-up of the engine and means to variably determine the duration of the temporary open-loop control according to the detected degree of warm-up of the engine.

Abstract: An air-fuel ratio control system for an internal combustion engine. Excessive fuel supplying at fuel cut reset time is avoided, by interrupting the fuel supply when a fuel cut control signal is being output. An amount of fuel cut time during which the fuel cut control signal is output is determined, and a hold time is also determined. This hold time corresponds to an amount of time necessary for combustion gas to reach a feedback sensor, and be included in the feedback control signal, after termination of the fuel cut. A feedback or closed loop system is used during normal operations. An open loop control signal is used during fuel cut time, and for a period of time equivalent to the value of the hold time after the end of this fuel cut time. Therefore, open loop control is used until exhaust gases have again reached the feedback sensor so that feedback or closed loop control can thereafter be used.

Abstract: In the fuel control for an engine for which cut off of fuel supply is performed while the engine is in the decelerating operation condition, at the time of fuel cut off termination, an injection of fuel through a fuel injector into an intake system of the engine is supplied at substantially the same time as stopping the fuel cut off, wherein the amount of such fuel injection is controlled according to the temperature of the air being sucked into the engine intake system so as to be decreased as the air temperature increases.

Abstract: In a fuel injection control system which cuts off the fuel supply under certain zero-engine-load conditions, a single asynchronous fuel injection is performed immediately in response to a fuel resumption request. Fuel resumption is ordered when, for example, a throttle valve opens from its idling position or when engine speed drops too low. The single asynchronous fuel injection is performed immediately and with an enhanced fuel quantity to ensure prompt and adequate response to changing engine conditions. Normal, synchronous fuel injection timing is adjusted following fuel resumption to match, or at least not to interfere with, the timing of the asynchronous fuel injection.

Abstract: A system and method for controlling a fuel supply to a vehicular internal combustion engine, in which a predetermined threshold value at which a fuel supply cutoff zone of the engine is initiated is varied so as to provide an optimum range of the fuel cutoff zone according to a magnitude of the engine deceleration and the variation of the predetermined threshold value is learned and stored for the subsequent use as the predetermined threshold value to cope with a characteristic change of the system including the engine and engine output power transmission. When the magnitude of the engine deceleration is large, the predetermined threshold value is increased so as to avoid repetition of fuel supply cutoff and fuel supply resumption which affects adversely the engine driveability. When the magnitude is small, the predetermined threshold value is decreased i.e., made closer to another predetermined threshold value at which a fuel supply recovery is carried out so as to extend the fuel supply cutoff zone.

Abstract: A fuel injection control device for an internal combustion engine in which a fundamental fuel injection amount is set according to suction air amount per one revolution of the engine Q/N. The fuel injection control device includes a transitional operation start timing detector for detecting an acceleration start timing or a deceleration start timing, an engine rotational number measurer for measuring a predetermined number of rotations of the engine from the acceleration start timing or the deceleration start timing, a throttle valve angle detector for detecting that a throttle valve angle is out of a set range, and apparatus for setting an upper limit value and/or a lower limit value of Q/N when the throttle valve angle detector generates a signal showing that the throttle valve angle is out of the set range until the engine rotational number measurer measures the predetermined number of rotations of the engine.

Abstract: To provide for smooth operation of a fuel injected engine, typically a diesel engine, if the diesel engine is controlled to reduce speed and towards idling thereof, it is first determined if the actual speed (n) of the engine drops below a certain speed threshold (NS), the commanded speed (N), upon such sensed occurrence is evaluated and the time rate (1/K) of an exponential function of commanded rate of drop in engine speed is changed as a function of the decrease (dn/dt) of the actual speed of the engine. Engine temperature can be used to modify the speed threshold, and the rate of change can, additionally, be evaluated with respect to a predetermined rate of change of speed of the engine. A difference between commanded and actual speed, applied to a proportional-integral controller can be used with an offset which offset becomes effective only upon rise of engine speed after a prior drop.

Abstract: Disclosed is a system for supplying fuel to a vehicular internal combustion engine and method therefor, wherein the speed of the vehicle is detected from an instantaneous revolution speed of an output axle of a transmission of the vehicle, a gear shift position of the transmission is detected, a first engine speed at which the supply of fuel to the engine is to be cut off is determined on the basis of the detected instantaneous revolution speed of the output axle of the transmission and the gear shift position of the transmission, the first engine speed is compared to a preset second engine speed at which the supply of fuel is to be resumed following the cut-off of the supply of fuel to the engine, and the supply of fuel is cut off only when the first engine speed exceeds the preset second engine speed.

Abstract: There is a method for controlling the fuel supply of an internal combustion engine having a throttle valve in the intake air system. It is detected that an angular position of a crankshaft of the engine coincides with a predetermined crankshaft angular position. Whenever this coincidence is detected, the pressure in the intake air passage downstream of the throttle valve and the engine rotating speed or the value of the inverse number thereof is detected on the basis of the interval between the detections of the crankshaft angular position. The reference basic fuel supply amount which is to be supplied to the engine is determined in accordance with the present detection value P.sub.BAn of the pressure in the intake air passage. The present reference value M.sub.eAVEn having a predetermined functional relationship to the present detection value M.sub.en and previous reference value M.sub.eAVE(n-1) of the engine speed or of the value in inverse proportion thereof is set.

Abstract: An engine control system is disclosed which includes engine idle speed control apparatus which implements a closed loop idle speed control by varying the amount of air provided to the engine by an air bypass valve. The control system develops an engine torque polarity signal related to the difference between actual current manifold air pressure and the average of the manifold air pressure which exists during engine idle. The torque polarity signal is utilized to implement engine deceleration control by selectively providing additional air and/or reduced fuel to the engine to implement engine fuel mixture enleanment during deceleration conditions. The engine idle speed control apparatus calculates an error signal related to the difference between actual engine speed and a calculated desired engine idle speed.

Abstract: A fuel supply control system for an automobile engine comprises a detector for detecting change in engine operating condition, a fuel adjuster for variably controlling the amount of fuel to be supplied to the engine, an A/F ratio setting device for setting the lower or higher A/F ratio of a combustible mixture than the critical A/F ratio to a higher or lower A/F ratio than a critical A/F ratio at which the engine can produce substantially the same or intermediate torque as that produced by the same engine with the supply of such combustible mixture, and a control operable in response to an output from the detector to control the fuel adjuster in such a way that, at the time the engine is desired or required to be switched from one engine operating condition to another, the A/F ratio lower or higher than the critical A/F ratio can be rapidly adjusted to the higher or lower A/F ratio set by the A/F ratio setting device and, thereafter, the A/F ratio can be progressively adjusted to a target or desired value.

Abstract: In an internal combustion engine, fuel enrichment is carried out when an acceleration state occurs after a transition from a fuel cut-off state to a fuel cut-off recovery state, the fuel enrichment is determined by taking into consideration the amount of fuel supplied to the engine between the above-mentioned transition and the occurrence of the acceleration state.

Abstract: An air-fuel ratio control system for an internal combustion engine has an electromagnetic valve for correcting the air-fuel ratio of air-fuel mixture, and an O.sub.2 sensor for detecting oxygen concentration in exhaust gases. A detecting circuit is provided for producing an acceleration signal when the engine is accelerated at cold engine operation. A pulse generating circuit is provided for producing a plurality of pulses, the duty ratios of which are proper for air-fuel ratio at acceleration in cold engine operation. A changeover switch is provided to respond to the acceleration signal for applying the pulses to the electromagnetic valve so as to control the air-fuel ratio.

Abstract: An air-fuel ratio control system for an internal combustion engine has an electromagnetic valve for correcting the air-fuel ratio of air-fuel mixture, an O.sub.2 sensor for detecting oxygen concentration in exhaust gases, and a feedback control circuit including a PI circuit, and a pulse generating circuit responsive to the output of the PI circuit for generating pulses, the duty ratio of which is dependent on the output of the PI circuit. A steady state detecting circuit is provided for producing a steady state signal when the magnitude of acceleration of the engine is within a predetermined range. The constant of the PI circuit is decreased by the steady state signal for preventing overshooting of the air-fuel ratio control.

Abstract: The invention is directed to a method and an apparatus for controlling the overrun mode of operation of an internal combustion engine, wherein instantaneous values of the relevant negative speed change of the internal combustion engine are sensed and evaluated to control the overrun mode. In this arrangement, a higher resume speed which is selected on commencement of the overrun mode and reduced to a lower speed limit after a predetermined time function, can be shifted additionally in dependence on the negative speed change. Further, to keep an internal combustion engine from stalling, the actual value of the negative speed change can be compared with a predetermined desired value; if it exceeds that value, the decision for a resume of fuel delivery can be made without delay.

Abstract: An electronically controlled fuel injection apparatus in which opening degree of a throttle valve or throttle aperture is sampled periodically at a predetermined time interval to detect change in the throttle aperture for determining deceleration. Upon every determination of the deceleration, a correcting quantity is accumulatively determined so that deceleration is corrected for compensating delay in the control of fuel injection in dependence on magnitude of change in the throttle aperture. An improved engine performance and optimum air-fuel ratio control can be accomplished.

Abstract: A method for controlling the fuel supply of an internal combustion engine having a throttle valve in the intake air system is provided. It is detected that the crankshaft of the engine is at a predetermined crankshaft angular position. At every detection of this crankshaft position, the pressure in the intake air passage downstream of the throttle valve is detected. The present reference value P.sub.BAVEn having predetermined functional relations regarding the present detection value P.sub.BAn of the pressure in the intake air passage and the preceding reference value P.sub.BAVE(n-1) is set. The amount of the fuel supply into the engine is determined on the basis of this present reference value P.sub.BAVEn. The presumptive value of the intake air absolute pressure is calculated in consideration of the correction values with respect to the time lag in control operation and to the fuel deposition on the wall surface in the intake air manifold.

Abstract: A controlling method for pulse application to an actuator using a digital controller.A controlling method of an actuator, wherein a deviation is obtained from a command value and its feedback value, the absolute value of said deviation is determined whether it is larger than the minimum reference deviation corresponding to the dead zone, and only when the absolute value of the deviation is larger than the minimum reference deviation, the actuator is driven by a pulse having an application period proportional to the absolute value of the deviation plus a minimum application period stored in the memory of the digital controller.The minimum application period stored in the memory is increased or decreased and renewed depending on the judgement whether the movement volume of the actuator at each pulse application was under, proper or over.

Abstract: An air-fuel control system determines a basic injection amount for steady operation in accordance with an engine speed and an intake manifold pressure or intake air amount of the engine, and compensates during a transient period of engine operation the basic injection amount in accordance with engine operating conditions such as throttle valve opening, O.sub.2 concentration in the exhaust gas, etc. At the time of engine acceleration, the fuel increment is incrementally compensated for in accordance with the air-fuel ratio immediately before the acceleration, data for fuel increment being stored in a map corresponding to data of the basic injection amount.

Abstract: A control apparatus for diesel engines controls the energization of glow plugs each of which is disposed in a cylinder of a diesel engine and heated by an energizing current flowing therethrough. When fuel supply to the engine is resumed after the engine temperature has fallen due to the interruption of fuel supply during a decelerating operation of the engine and further when fuel supply is enriched during an accelerating operation of the engine while it is cold, the control apparatus controls the energization of the glow plugs, thereby promoting the combustion of the engine and improving the combustion efficiency of the engine.

Abstract: A fuel cut-off device for an internal combustion engine having a fuel supply means into the engine. The device comprises a fuel cut-off means for cutting the supply of fuel to protect the engine from an abnormal rpm rate when the engine speed exceeds a fuel cut-off reference value at a relatively higher speed range. The device further comprises a racing condition detecting means and a means for determining the fuel cut-off reference value to provide a first value for the loaded condition of the engine and a second lower value for the racing condition of the engine. In the racing condition, the fuel cut-off reference value is further progressively reduced.

Abstract: An apparatus is provided for controlling the supply of fuel to internal combustion engine having a control valve for controlling the amount of air to be supplied to an engine piston downstream of a throttle valve. The apparatus comprises a detector for detecting any disorder in the amount of air and for providing a disorder indicating signal. An engine speed sensor detects the rotating speed of the engine and a throttle opening sensor detects the degree of opening of the throttle valve. A fuel cut circuit is coupled to the disorder detector, the engine speed sensor, and the throttle opening sensor for storing a fuel cut area defined by the degree of throttle opening and the rotating speed of the engine. The fuel cut circuit produces, in response to the disorder indicating signal, a fuel cut command signal when the outputs of the engine speed sensor and the throttle opening sensor indicate that the engine is operating within the fuel cut area.

Abstract: An engine air-fuel ratio control system in which the engine operating range is divided into a light load, medium load and heavy load regions. In the light load region, a control of the fuel supply is made so as to provide a mixture of leaner than the stoichiometric value. In the medium load region, a feedback control is made based on the signal from an O.sub.2 sensor and, in the heavy load region, a control is made to provide a richer mixture. In the transient between the light load and medium load regions, the air-fuel ratio is changed with a rate which changes in accordance with the rate of change in the engine load.