Abstract: A method for controlling the supply of fuel and ignition spark for an internal combustion engine. The supply of fuel which is mixed with air is cut off upon engine deceleration and resumed thereafter. At the transition from the cut-off to resumption of supply of fuel, the timing of ignition spark which ignites the mixture of air and fuel is retarded enough to prevent an abrupt increase in an engine output torque. The retarded timing of ignition spark is then advanced gradually as the time passes so that the engine output torque increases gradually.

Abstract: An engine control system which controls the engine fuel injection amount and the ignition timing by being supplied with and processing the rotational speed signal produced on the basis of the output of a rotational speed sensor producing the rotational speed signal at every predetermined engine crank shaft angle and an intake air amount signal from an air amount sensor for detecting the intake air amount of the engine. At certain predetermined engine rotational angles, the rotational speed signal and the intake air amount signal are read and compared with the previously-read rotational speed signal and intake air amount signal respectively, thus detecting changes therein respectively. These changes and signal values are used to correct control signals for ignition timing and fuel injection amount.

Abstract: An ignition control device for changing the ignition timing of an internal combustion engine during and after the occurrence of engine braking, i.e., during a condition of increased speed and low load, as during coasting. The device includes a circuit which receives signals related to engine load and engine speed and determines therefrom the onset of engine braking. The device then retards the engine timing so as to reduce the amount of positive engine torque, whereafter the fuel supply may be entirely shut off. Upon establishment of normal operation or idling, the fuel supply is restored and the ignition timing is gradually returned to the normal setting.

Abstract: A method and apparatus for controlling the fuel supply of an internal combustion engine in which the primary fuel injection valve control pulses are derived on the basis of signals from sensors which monitor various engine variables, e.g. intake air flow rate, induction tube pressure, engine speed and/or engine and air temperatures and in which the fuel supply is entirely interrupted during the condition of engine overrunning (negative output torque). After the termination of engine overrunning, the normal fuel quantity which would be supplied on the basis of prevailing sensor signals is intentionally increased for a predetermined length of time to compensate for engine cooling during overrunning. This is done by increasing the pulse length of the injection control pulses. The apparatus includes transducers and circuits for recognizing the condition of overrunning and circuitry for supplying temporarily lengthened fuel control pulses.

Abstract: A system for increasing the amount of fuel injected into an internal combustion engine in response to an increase in the manifold absolute pressure greater than a predetermined amount and greater than a predetermined rate. The amount of enrichment is equal to a first value determined by the engine coolant temperature increased by a factor that has an initial value determined by the rate of increase in the manifold absolute pressure and that is varied toward unity at a rate determined by engine temperature. The duration of acceleration enrichment is determined by the amount of change in the manifold absolute pressure and the engine coolant temperature.

Abstract: An engine air and fuel controller for a vehicle internal combustion engine is described wherein the mass fuel flow rate is controlled directly in response to vehicle operater command. The engine throttle is positioned by an electronic controller in response to the fuel flow rate to achieve a mass air flow rate determined to produce a scheduled air/fuel ratio. The controller includes a circuit which is responsive to the engine speed to limit the minimum value of the commanded fuel flow rate in accord with a predetermined schedule at a rate whereat the engine throttle is controlled to a scheduled open position during engine overrun conditions to improve engine operation.

Abstract: An improved electronic control fuel injection system is disclosed wherein, during acceleration, fuel of a given amount is supplied to an engine which is commensurate with a sum formed of the amount of fuel to be burned with air in a combustion chamber, and an amount of fuel to be consumed so as to wet or moisten the inner surfaces of an intake port and the like which have been dried due to a prolonged interruption in the supply of fuel to an engine during a preceding deceleration condition. The fuel supplied to an engine through an injection valve operated by the disclosed fuel injection system at the beginning of acceleration immediately subsequent to the interruption of the fuel supply for a predetermined duration forms, with the incoming air, a desired air-fuel ratio, so that a mixture charge may be burned at the beginning of the acceleration without engine misfires occurring.

Abstract: An air flow rate compensation circuit is provided to compensate for an erroneous air flow rate signal produced in response to the movement of the flap of an air flow meter disposed in the intake air passage of an internal combustion engine where the erroneous nature of the signal occurs because of an overshoot characteristic of the flap. The compensation circuit produces an output signal with which either an air/fuel ratio control signal produced in response to the air flow rate signal or the air flow rate signal per se is modified where the output signal is produced in response to the movement of the throttle valve or the variation of the air flow rate signal.

Abstract: A fuel injection system for an automotive internal combustion engine equipped with a fuel cut off control signal generator comprises a smoothing circuit which smoothes a fuel cut off control signal produced in response to engine parameters. The flow rate of fuel injected via injection valves is controlled in accordance with the pulse width of a valve energization signal where the pulse width thereof is further controlled by the voltage of the fuel cut off control signal so that the fuel flow rate decreases and increases exponentially in the same manner as the voltage of the fuel cut off control signal when the fuel flow is cut off and is reestablished. Two monostable multivibrators and two transistors are provided for selectively transmitting and blocking the fuel cut off control signal so as to prevent misfires of the engine when the fuel flow rate is below a predetermined value.

Abstract: In an electronic fuel injection system for an internal combustion engine, a throttle position sensor provides an output pulse with a duration corresponding to the time interval during which throttle is nearly closed. The output from the throttle position sensor is nullified when the pulse duration is smaller than a predetermined value to prevent fuel cut-off during brief closure of throttle during transmission gear changes. The output from the throttle position sensor is used to cut off fuel only when the throttle closure time extends beyond the predetermined time interval.

Abstract: A fuel injection system equipped with a fuel increase command signal generator for an automotive internal combustion engine, comprising an airflow meter for measuring the airflow rate of the intake air for determining the pulse width of a pulse signal with which fuel injection valves are energized; and a fuel increase command signal generator for producing a command signal with which the fuel flow rate is momentarily increased. The fuel increase command signal generator includes a differentiator and a comparator for detecting the rate of decrease of the airflow, another comparator for detecting the opening degree of the throttle valve of the engine, and an AND gate for producing the fuel increase command signal so that the fuel flow rate is increased only when the rate of decrease of the airflow is over a predetermined value while the throttle valve is closed or nearly closed.

Abstract: An electronic control unit for regulating the air/fuel ratio of an internal combustion engine is disclosed. The electronic control unit has an open loop calibration for regulating the air/fuel ratio that is corrected with a closed loop correction signal developed by an integral controller. The open loop calibration is a speed-density based schedule which is combined with corrections for special conditions to account for the operating parameters of the engine at any instant. Included in these special condition corrections are provisions for increasing the air/fuel ratio upon a deceleration sufficient enough to cause a rich air/fuel ratio breakthrough because of the EGR valve lag time. A deceleration detector senses decelerations in excess of this predetermined amount by measuring the rate of change of the pressure in the intake manifold of the engine. A fixed percentage increase in air/fuel ratio is switched into the open loop calibration when the deceleration exceeds the amount required for breakthrough.

Abstract: An electronic fuel injection control apparatus for an internal combustion engine mounted on an automotive vehicle. In a vehicle system where the amount of fuel injected to the engine is electronically calculated from the rotation speed and the amount of sucked air at every rotation of the engine, the operating condition of the engine is monitored and discriminated as to whether the monitored operating condition is in a predetermined operating range where the surge of the automotive vehicle is apt to occur due to the resonance between the change in the output torque of the engine and the vehicle mechanical structure.