Abstract: A premixing apparatus in which a downstream end of a gas supply passage having interposed therein a flow control valve is connected to a gas suction section disposed in an air supply passage on an upstream side of a fan. The premixing apparatus has: a butterfly valve as an air resistance changeover device for changing over, between high and low, a ventilation resistance in that section of the air supply passage which is on the upstream side of the gas suction section; and a gas resistance changeover device for changing over, between high and low, a ventilation resistance in that section of the gas supply passage which is on the downstream side of the flow control valve. Wind noises at the time of closing the butterfly valve can be prevented.

Abstract: A premixing apparatus in which a downstream end of a gas supply passage having interposed therein a flow control valve is connected to a gas suction section disposed in an air supply passage on an upstream side of a fan. The premixing apparatus has: a butterfly valve as an air resistance changeover device for changing over, between high and low, a ventilation resistance in that section of the air supply passage which is on the upstream side of the gas suction section; and a gas resistance changeover device for changing over, between high and low, a ventilation resistance in that section of the gas supply passage which is on the downstream side of the flow control valve. Wind noises at the time of closing the butterfly valve can be prevented.

Abstract: A diagnostic system for detecting a freezing condition of an intake pressure sensor for an engine includes a control unit for checking engine operating parameters after a turn-on of an ignition switch to determining whether the engine is a predetermined state permitting a freeze diagnosis, and for performing the freeze diagnosis only when the engine is in the predetermined state. The control unit monitors a decrease of the intake pressure sensed by the intake pressure sensor as the engine speed increases from a start, and judges a freezing condition to exist if the intake pressure does not become sufficiently low even after the engine speed becomes higher than a predetermined speed level.

Abstract: An object of the present invention is to be able to correct for deviation of an actual air-fuel ratio from a point for satisfactory purification performance of an exhaust gas purification catalytic converter, during an interval from immediately after start up until an air-fuel ratio sensor and an exhaust gas purification catalytic converter attain a stable condition. To achieve this, a control constant in an air-fuel ratio feedback control is set and altered during an interval from immediately after start up until the air-fuel ratio sensor and the exhaust gas purification catalytic converter attain a stable condition. In this way, the actual air-fuel ratio can be shifted, and hence the deviation of the actual air-fuel ratio from the point for satisfactory purification performance of the exhaust gas purification catalytic converter during the interval from immediately after start up until the air-fuel ratio sensor and the exhaust gas purification catalytic converter attain a stable condition, can be corrected.

Abstract: A period of from when the starter switch is turned on or from the start of the fuel injection until when the engine rotation speed has reached a predetermined rotation speed, is detected as a parameter representing the starting performance. After the engine rotation speed has reached a predetermined rotation speed, furthermore, the parameter representing a change in the rotation and the parameter representing rising gradient of the rotation-speed are detected. Then, the parameter representing the starting performance, the parameter representing a change in the rotation and the parameter representing a rising gradient of the rotation speed are weighted to detect the fuel property.

Abstract: A reference angle signal which provides a reference for ignition control of each cylinder is output together with a cylinder discrimination signal for matching the reference angle signal with the respective cylinder, and ignition control carried out for separate cylinders on the basis of the cylinder discrimination results from the cylinder discrimination signal. When there is an abnormality in the cylinder discrimination signal and cylinder judgment becomes nonfunctional, the reference angle signal is matched with the respective cylinder in the ignition order under the normal conditions up until the occurrence of the abnormality, and ignition is carried out normally in the separate cylinders. As a result, even if cylinder discrimination by the cylinder discrimination signal becomes nonfunctional, ignition for separate cylinders can be continued, so that the engine can keep running.

Abstract: An electronic control fuel injection apparatus for a crank chamber compression type 2-cycle engine which compensates a fuel injection amount predetermined by an opening degree of an engine intake air system and an engine speed in response to a fuel amount reduction rate allocated by using a opening degree of the engine intake air system and an engine speed if the engine speed enters an acceleration loss region during a predetermined deceleration and or re-acceleration of the engine while a deceleration of the engine is detected.

Abstract: An apparatus supplies assist air toward an injection nozzle of a fuel injection valve of an internal combustion engine, to atomize an injected fuel. The apparatus starts and stops supplying the assist air according to engine operating conditions while correcting ignition timing or an engine intake air quantity, to thereby suppress fluctuations in engine output.

Abstract: A starting time engine speed control device is provided for controlling fuel to be injected by correcting an amount thereof within a predetermined period of time after the start of an internal combustion engine using a starting time fuel injection control with respect to a basic fuel control. The engine is mounted on a vehicle and has a clutch mechanism which is coupled when engine speed exceeds a coupling engine speed, and the starting time engine speed control device includes a control arrangement adapted to control the fuel to be injected by gradually increasingly correcting the amount thereof in accordance with increasing engine speed up to said coupling engine speed using the starting time fuel injection control.