Abstract: A fuel injection control device in which a needle valve of a fuel injector is opened and closed by two valves. The fuel injector has a pressure control chamber and a fuel chamber, and the needle valve opens a fuel injection aperture to inject the fuel in the fuel chamber to the engine when a pressure in the pressure control chamber is relatively high. One valve is provided in a passage which connects a pump, the pressure control chamber, and a reservoir, and the other valve is provided in a passage which connects the pump, the fuel chamber, and the reservoir.

Abstract: A fuel injection system for a diesel engine has fuel pump driven by the engine for producing highly pressurized fuel, a common rail for storing the pressurized fuel therein and injection nozzles for injecting the pressurized fuel stored in the common rail into the engine. The injection nozzles are electrically controlled in accordance with engine operating conditions (N, .alpha.) by the use of injection control solenoid valves provided between the injection nozzles and the common rail. The fuel pump is electrically controlled in accordance with the engine operating conditions by the use of a spill control solenoid valve which spills the pressurized fuel to a low pressure fuel channel so that loss of engine torque required by the pump is reduced.

Abstract: A control system for an engine has a temperature sensitive element as part of a device for measuring the air flow in an air intake manifold to the engine. Further, a first pulse signal is generated, corresponding to the rotation of the engine, for controlling the setting of a flip-flop. A transistor is conducted in the set state of the flip-flop to supply a heating electric current to the element. The element supplied with the current is raised to the temperature that corresponds to the air flow in the manifold. When the temperature of the element is raised until the specified temperature difference to the air temperature (measured by a sub temperature sensitive element) is set, the temperature difference is detected by a comparator, and the flip-flop is reset by the detection signal.

Abstract: An apparatus for controlling fuel injection timing, for use in a fuel injection pump of a diesel engine, comprises a toothed wheel coaxially and fixedly mounted on a drive shaft of the fuel injection pump, first and second detectors for detecting the rotational position of the tooth wheel, and a control unit, having a microcomputer, for actuating a fuel injection timing changer of the pump according to the phase difference between signals from the first and second rotational position detectors for controlling fuel injection timing. The first rotational position detector is fixedly mounted on a pump housing and the second rotational position detector is fixedly mounted on a member rotatably provided around the drive shaft of the pump. The member is generally used for converting the rotational movement of the drive shaft to the reciprocation of a plunger of the pump which supplies fuel into cylinders of the engine. The phase difference corresponds to the actual injection timing condition.

Abstract: A gas sensor of constant-current type is used to detect a gas component in exhaust gases from an internal combustion engine so as to perform feedback control of air/fuel ratio of an air-fuel mixture supplied to the engine. In order to detect an air/fuel ratio which is richer than a stoichiometric value, a voltage applied to the gas sensor is set to a high value so that the gas sensor does not exhibit a constant-current characteristic. In the case it is desired to detect an air/fuel ratio which is either richer or leaner than the stoichiometric value, the voltage may be changed between the high value and a lower value at which the gas sensor exhibits a constant-current characteristic. Engine parameters are detected to determine whether the engine requires a rich mixture or a lean mixture, and the voltage may be changed as the result of such determination.

Abstract: The idle speed of an internal combustion engine is controlled in response to a variable ignition timing control signal from a microcomputer. The microcomputer derives this control signal as a function of the magnitude of engine speed variation which occurs during engine idle periods to cause the ignition timing to vary quickly in response to a transitory engine load variation. An auxiliary air delivery system may be advantageously incorporated in the idle speed control system to cooperate with the ignition timing control in response to the engine speed variation.

Abstract: The timing of spark ignition is set in normal operating conditions at a programed spark advance angle corresponding to the MBT (minimum spark advance for best torque). When knocking of the engine is detected by a vibration sensor, the ignition timing is delayed by a predetermined amount, e.g., 2.DELTA..theta., for each engine cycle that knocking is detected in synchronism with the rotation of the engine. When knocking is not detected, the ignition timing is advanced by another predetermined amount, for each engine cycle that knocking is not detected. e.g., .DELTA..theta.. In this method for controlling the spark timing, the amount of retardation, 2.DELTA..theta., is selected to be larger than the other amount of advance, .DELTA..theta..

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: A spark-ignition timing of the internal combustion engine is normally set at an MBT (minimum spark advance for best torque). However, when a knocking of the engine is detected by a vibration sensor fixed to the engine, the ignition timing is retarded with respect to the MBT by an angle corresponding to either a non-knocking limit retard angle or a maximum retard angle determined by engine operating conditions whichever is smaller.

Abstract: A method of detecting knocking intensity of an internal combustion engine uses a detector for detecting vibration propagated within the engine and a first calculation circuit for obtaining an average value of vibration sensed by the vibration detector within a predetermined crank angle before the top dead center, and in which knocking is identified when the ratio between the above average value and the maximum value of vibration after the top dead center exceeds a predetermined value.

Abstract: A method of controlling the timing of spark ignition for an internal combustion engine by monitoring the magnitude of vibration of the engine caused when the engine is knocking. A vibration sensor is mounted on the engine to detect the magnitude of the engine vibration, and the average value of the magnitude of vibration of the engine prior to the engine piston arriving at the top dead center position is compared with the instantaneous value of the magnitude of vibration of the engine caused after the arrival of the piston at the top dead center position. Consequently, when the instantaneous value of the vibration is greater than the average value of the vibration, the spark timing is retarded to prevent the occurrence of knocking in the engine. To accurately detect knocking in the engine, the average value of the vibration is obtained by dividing the integrated value of the monitored vibration by the monitoring time.

Abstract: A system for controlling the amount of air taken in by an engine comprises an air duct tube bypassing a throttle valve of an intake tube for taking in air supplied to an automobile engine, a plurality of valves for regulating the amount of air passing through the air duct tube, and control device therefor. The amount of air in the bypass is controlled in accordance with the temperature and number of revolutions of the engine and the air intake pressure downstream of the throttle valve. During the idling of the engine, the air intake control system generates a signal representing the standard engine idling revolutions in accordance with the engine temperature, compares the actual engine revolutions with a reference, and regulates the amount of air flowing in the bypass by use of the results of a comparison, thus rendering the actual engine revolutions identical to the reference.

Abstract: A method for controlling the ignition timing for the internal combustion engine is disclosed. When it is decided that the engine load is large on the basis of the engine number of revolutions per minute and intake pressure. If the engine is in the knocking condition, a step lead angle is added to the present lead angle value in the range between a set lead angle and a minimum lead angle. If the engine is not in the knocking condition, on the other hand, a step lead angle is subtracted from the present lead angle value in the above-mentioned range. By contrast, when it is decided that the engine load is small on the basis of the engine r.p.m. and intake pressure. The lead angle control of the present lead angle value is stopped so that the present lead angle is set at the above-mentioned set lead angle or the minimum lead angle value.

Abstract: A fuel injection system for an internal combustion engine comprises a fuel metering means operative to meter and adjust the flow of fuel to the engine in accordance with the operating conditions of the engine, fuel injection nozzles disposed in respective intake ports of engine cylinders, a fuel distributor operative to distribute the metered and adjusted flow of fuel to the respective injection nozzles, an advancer responsive to the increase in the speed of the engine operation to advance the fuel distribution timing of the distributor, and a fuel distribution timing varying means responsive to the variation in the load on the engine to vary the fuel distribution timing of the distributor.