Abstract: A fuel injection system includes a valve for supplying fuel to an internal combustion engine; a device for measuring the quantity of air passing through an air intake passageway in both forward and backward directions; a device for detecting the number of revolution of the engine; a device for detecting conditions of the engine; a limiting device, which is used when an output therefrom produces a time width of a pulse to be imparted to the fuel injection valve, and which limits variables related to the atmospheric pressure including a measured value of the air quantity limited by the number of engine revolutions; and an atmospheric pressure conformed corrective value computing device.

Abstract: An electronic control system for an internal combustion engine, in which parameters necessary for the engine control are found by use of auxiliary quantities to thereby control the operating characteristic quantities of the internal combustion engine, the electronic control system comprising: a memory device for storing in advance, in the form of a two-dimensional map, a charging efficiency per se or related values of the charging efficiency corresponding to a degree of opening of the throttle valve and a number of engine revolution under the reference atmospheric condition; and a computing device for computing atmospheric pressure related values which include therein at least the atmospheric pressure value and are dependent on the atmospheric pressure, in accordance with a predetermined computation equation which takes a ratio of the charging efficiency per se or related values of the charging efficiency to be found out by selective use of signals of the intake air flow rate and a number of revolution of the

Abstract: An engine control method and device for a vehicle are disclosed in which jerk in the body of a vehicle developing upon acceleration or deceleration thereof can be always made substantially constant so as to improve riding comfort. Also, pitching or surging of the vehicle body during acceleration or deceleration thereof is substantially alleviated or suppressed even when the operator abruptly operates an accelerator pedal, thereby further improving riding comfort. To this end, a target degree of opening of a throttle valve is first set based on at least one of the sensed amount of accelerator pedal operation, the sensed engine load condition and the sensed number of revolutions per minute of the engine. The throttle valve operatively associated with the accelerator pedal is controlled in such a manner that, when the accelerator pedal is operated by the operator, the throttle valve is operated to move to the target degree of opening in synchronization with the intake stroke of the engine as sensed.

Abstract: A apparatus for controlling the number of the rotation of an internal combustion engine, which is capable of feeding air-suction quantity back to the objective value and provided with memory storing and retaining the feedback value when the feedback operation is stopped. When faster adjustment is needed at the moment of resuming the feedback operation or performance characteristic of the air-suction control system largely varies during service period, the apparatus securely retains the feed-back value and applies it as the initial value to allow the engine to securely reactivate satisfactory startup operation.

Abstract: In an rpm control device for an internal combustion engine, a loop for adjusting a suction rate of the engine to a target value and a loop for adjusting a speed (rpm) of the engine to a target value are operated in combination, so that the suction rate and the engine speed are adjusted quickly.

Abstract: Signals from a intake air quantity sensor disposed in the intake air passage of an internal combustion engine are calculated to obtain a basic value corresponding to an amount of fuel required for the engine; the basic value is corrected by a negative feed-back control on the basis of the output of an air-fuel ratio sensor so as to obtain a desired air-fuel ratio to thereby supply the fuel to the engine by controlling a fuel control valve. A fuel control device comprises a writing means for writing in a memory a value of negative feed-back correction or a value related thereto when the output of the intake air quantity sensor is in the vicinity of a representative point, a correcting means for correcting the basic value on the basis of data in the memory and a valve controlling means to close a control valve which controls feeding of vaporized fuel caught in a canister to the air intake system of the engine when the value of negative feed-back corection or the value related thereto is written in the memory.

Abstract: An idling engine speed controlling apparatus has a feed-back control system to regulate engine speed to a target speed such that a torque disturbance is directly detected to convert it into a signal so that an air-flow rate or ignition timing is controlled on the basis of the sum of the signal and a time-differential of the signal, or such that sub-feed-back compensation is given to the output end of a proportional and integral controller so that an amount of air flowing in a intake air conduit is compensated with the first-order-lag component or an amount of air is controlled in response to the first-order-lag component or the second-order-lag component or the sum of or the difference between these components, or such that an output from the proportional and integral controller or an output from the actuator is fed back to the input side of the controller so as to include a transfer function of the actuator through a detection circuit.

Abstract: A rotational frequency control apparatus of an internal combustion engine comprising a bypass route bypassing a throttle valve provided to an intake pipe of internal combustion engine, an intake control valve which controls an intake amount of this bypass route, an intake drive and control device which drives and controls open and close conditions of this intake control valve, and moreover, an intake amount sensor which detects the intake amount of the intake pipe, a rotational frequency sensor which detects a rotational frequency of the engine, a rotational frequency adjusting part which generates a target intake amount based on an actual rotational frequency detected by the rotational frequency sensor and a target rotational frequency, an intake amount adjusting part which outputs an intake control signal based on the target intake amount and the actual intake amount detected by the intake amount sensor, a switching part which causes both adjusting parts to make output operations under an unloaded condition

Abstract: A fuel control device for internal-combustion engines in which a proper correction value is calculated from the contents of memories corresponding to adjacent representative points, meeting every condition of the amount of mixture drawn in, by selecting representative points to represent the tendency of a flow-dependency characteristic change of intake sensor output, thereby obtaining a proper correction value in a region where the negative feedback of air-fuel ratio is controlled as well as in a region where the negative feedback can not be controlled.

Abstract: A system for controlling the operation of an internal combustion engine on the basis of air/fuel ratios and engine loads. A flow rate of intake air sucked into the engine and the cycle of engine revolutions are detected to determine an average flow rate of intake air, which is then used in cooperation with a compression ratio and an engine displacement to determine a net flow rate of intake air or the charging efficiency of the engine. This parameter represents a precise engine load and is used to regulate fuel injected into the engine. As a result, engine operations may be optimally controlled even during transitional operating states of the engine.

Abstract: A fuel control apparatus comprises a hot-wire type intake air quantity sensor disposed in an air intake passage for an internal combustion engine to detect the quantity of air passing therethrough, a burn-off control section for heating a hot wire at a temperature higher than a temperature in the normal operation, after the engine has been stopped, so as to burn off a deposit on the hot wire, wherein the operation of the burn-off control section is stopped when an output from the sensor exceeds a predetermined value. A signal indicative of a trouble in the sensor can be generated.

Abstract: A fuel control apparatus for an engine has a temperature sensor for detecting the temperature of the intake air to the engine, and is constructed to correct the upper limit value of the intake air amount preset in response to the operating characteristic of the engine in the operating range of the engine which does not exhibit the true value of the intake air amount by the detected output of the air flow sensor due to the reverse-flow effect of the intake air of the engine by the detected temperature by the temperature sensor.

Abstract: A fuel injection control system in which the output of a hot-wire air flow sensor is limited to a maximum value in order to compensate for return blow at low-speed, high-power conditions. However, the maximum value is adjusted for altitude and temperature.

Abstract: A novel and improved fuel-injection control system for an internal combustion engine capable of effecting minute or fine revisions of acceleration of an engine by appropriately processing an output signal from an AFS without employing a throttle sensor for detecting the opening degree of a throttle valve. The width of a basic injection pulse is calculated from the amount of intake air sucked into an internal combustion engine and the number of engine revolutions so that between the injection pulses synchronized with the number of engine revolutions, a series of special injection pulses having the calculated pulse width are generated for revision of engine acceleration.

Abstract: A fuel control apparatus for an engine has an atmospheric pressure sensor for detecting the atmospheric pressure in the vicinity of the engine, and is constructed to correct the upper limit value of the intaken air amount preset in response to the operating characteristic of the engine in the operating range of the engine which does not exhibit the true value of the intaken air amount by the detected output of the air flow sensor due to the reverse-flow effect of the intaken air of the engine.

Abstract: A fuel control system for an internal combustion engine capable of correcting an inlet air flow rate, used for the computation of a fuel injection, in consideration of a blow-back flow rate. The inlet air flow rate is detected by a hot-wire type sensor and sampled by a control unit. The control unit determines whether or not the sampled inlet air flow rate has reversed twice its gradient from the negative one to the positive one between predetermined crank angles of the engine and computes the blow-back flow rate subtracted from the inlet air flow rate.

Abstract: An RPM control apparatus for an internal combustion engine including a first limiter which suppresses an RPM feedback control signal indicating a target suction quantity or a target suction pipe pressure within a predetermined range that is set necessary and sufficient for covering a fluctuation range attributed to a no-load loss of the engine, and a second limiter which suppresses a suction feedback control signal on the basis of the output of the first limiter and an actual suction air quantity or suction pipe pressure within a predetermined range that is set necessary and sufficient for covering a fluctuation range attributed to the density of suction air, etc.

Abstract: An RPM control apparatus for an internal combustion engine capable of stopping the operation of an RPM adjuster which generates an RPM feedback control signal indicating a target suction quantity signal or a target suction pipe pressure signal for the engine in relation to the RPM of the engine and a target RPM thereof, and/or the operation of a suction adjuster which generates a suction feedback control signal in relation to the output of the RPM adjuster and an actual suction quantity or an actual suction pipe pressure of the engine, when at least one of the output of the adjusters exceeds a corresponding predetermined value.

Abstract: A fuel injection control apparatus for an internal combustion engine using a hot-wire type air flow sensor wherein, even during a low engine speed and in a fully opened condition of the throttle valve of the engine, the output of the air flow sensor is corrected corresponding to the opening of the throttle valve and the engine speed on the basis on a predetermined relationship therebetween, thereby providing a proper A/F ratio.