Abstract: An engine idling control apparatus having an idle switch which turns on/off in response to the open/close of a throttle valve and judging the idle state in accordance with the open/close operation of the idle switch. The idle switch state is judged by an idle switch state judging unit in accordance with the on/off the idle switch. When it is judged as the idle state, the max/min value of an output from a throttle valve sensor for detecting the opening degree of the throttle valve is detected by a max/min value detecting unit. A max/min value updating unit compares the detected max/min value with an already stored max/min value, and updates the already stored max/min value to store the updated max/min value. In accordance with the updated max/min value, a comparison reference value setting unit sets an idle judgement comparison reference value which is compared by an idle state judging unit with an output from the throttle valve sensor to judge if the engine is in an idle state or not.

Abstract: An automotive engine has a purge system for purging fuel vapor in a canister to an intake passage of the engine, and a learning control system. Fuel injection pulse width is determined by using a learning coefficient derived from learning memory. The learning memory stores a plurality of learning coefficients which are updated with change of characteristics of elements of the engine. When the purge starts, the learning coefficients stored in the learning memory are stored in an updating memory as updating coefficients. When the purge is cut off, the learning coefficients in the learning memory are updated with updating coefficients in the updating memory.

Abstract: Opposite first projections are formed on a crankshaft disk secured to a crankshaft of an engine on diametrically opposite positions, which correspond to top dead centers for specific positions at least two groups in which a pair of cylinders are in opposite phase to each other. A first sensor is provided for sensing the first projections and for producing a crank angle signal. Second projections are formed on a camshaft disk for representing the number of cylinders. A second sensor is provided for sensing the second projections for producing a cam angle signal. A specific cylinder is discriminated by a projection formed on the camshaft disk. In accordance with the crank angle signal and with the cam angle signal, operations for cylinder in each group is controlled at start of the engine. Further, in accordance with the cam angle signal and crank angle signal and with the discrimination of cylinder, the operation for each cylinder is independently controlled.

Abstract: A system for controlling ignition timing of an engine for adjusting ignition timing at an idling state of the engine. An ignition timing fixing switch is provided to produce a fixing signal for providing a fixed ignition timing. A comparator is provided for producing a vehicle driving signal when quantity of fuel injection is larger than a predetermined value which is sufficient for starting a motor vehicle. An AND gate is provided to respond to the fixing signal to produce a first switching signal and respond to the vehicle driving signal to produce a second switching signal. A changeover switch is provided to respond to the switching signal for providing a fixed ignition timing for the adjustment of the ignition timing and to respond to the second switching signal for providing an ignition timing dependent on operating conditions of the engine.

Abstract: An engine start control apparatus of the type that the running of the engine is controlled by a controller in accordance with data obtained from at least one sensor mounted on the engine and stored in a backup memory. The engine start control apparatus includes a starting condition detector unit for detecting a start ready state of the engine and outputting a start ready signal, a signal processing unit for processing an output signal from the sensor and storing the processed result into the backup memory in response to the start ready signal from the starting condition detector unit, a start detection unit for detecting the start of the engine and a power supply unit for supplying a power voltage to the controller in response to an output from the start detection means.

Abstract: A learning control system has a table storing learning coefficients in divisions thereof. An abnormality detecting system has a section for determining a number of updating times of coefficients in the table, and for determining a fact that a number of divisions in which each coefficient is out of a predetermined limit range is larger value than a predetermined second number. The section produces an abnormality signal when a coefficent exceeding the limit range in a particular division is updated a number of times more than a predetermined number of times. In accordance with the abnormality signal, all of coefficients in the table are held to a standard value.

Abstract: A knock control system for an automotive engine having a knock sensor for sensing the vibration of the engine, and a knock control unit responsive to an output signal of the knock sensor for retarding the ignition timing. The system is provided with a fail-safe circuit which produces a fail-safe signal for retarding the ignition timing upon the fault of the knock sensor, and an exhaust gas temperature sensor for producing a temperature signal when the exhaust gas temperature exceeds a predetermined temperature. A correcting circuit is provided to be responsive to the temperature signal for reducing the retardation degree determined by the fail-safe signal and a switching circuit further reduces the retardation degree when the engine rpm is greater than a predetermined value.