Abstract: The objective of the present invention is to provide a control device for an engine that enables precise control of the equivalence ratio. The system from the fuel injection amount to the output from a LAF sensor is modeled as an injection amount-sensor output model by means of a model equation containing model parameters and a lag coefficient. The system from the equivalence ratio to the LAF sensor output is modeled as a port equivalence ratio-sensor output model by means of a model equation containing the lag coefficient. The control device is equipped with: a feedback-use identifier that successively identifies values for the model parameters; a LAF lag compensation-use identifier that successively identifies values for the lag coefficient; and a stoichiometric driving mode controller that determines the value of a fuel injection amount.

Abstract: The objective of the present invention is to provide an exhaust purification system that is capable of purifying exhaust gas during both lean and stoichiometric driving. The exhaust purification system is equipped with: a feedback-use identifier, which identifies parameter values such that the error between the output value from a LAF sensor and the estimated value for the LAF sensor output as obtained from a model equation is minimized; and a stoichiometric driving mode controller. The controller performs feedback control and thereby determines the fuel injection amount such that in the stoichiometric driving mode the equivalence ratio value as calculated from the parameters reaches a target value which is set such that a three-way purification reaction occurs in an under-engine catalyst. The identifier identifies the model parameters before feedback control is initiated by the controller.

Abstract: The objective of the present invention is to provide a control device for an engine that enables precise control of the equivalence ratio. The system from the fuel injection amount to the output from a LAF sensor is modeled as an injection amount-sensor output model by means of a model equation containing model parameters and a lag coefficient. The system from the equivalence ratio to the LAF sensor output is modeled as a port equivalence ratio-sensor output model by means of a model equation containing the lag coefficient. The control device is equipped with: a feedback-use identifier that successively identifies values for the model parameters; a LAF lag compensation-use identifier that successively identifies values for the lag coefficient; and a stoichiometric driving mode controller that determines the value of a fuel injection amount.

Abstract: The objective of the present invention is to provide an exhaust purification system that is capable of purifying exhaust gas during both lean and stoichiometric driving. The exhaust purification system is equipped with: a feedback-use identifier, which identifies parameter values such that the error between the output value from a LAF sensor and the estimated value for the LAF sensor output as obtained from a model equation is minimized; and a stoichiometric driving mode controller. The controller performs feedback control and thereby determines the fuel injection amount such that in the stoichiometric driving mode the equivalence ratio value as calculated from the parameters reaches a target value which is set such that a three-way purification reaction occurs in an under-engine catalyst. The identifier identifies the model parameters before feedback control is initiated by the controller.

Abstract: A fuel injection quantity control device for use with a two cycle engine being rotatably driven by receiving a fuel-air mixture injected into the engine based on fuel injection quantity instruction signals and the air supplied through an intake passage and ignition of the fuel-air mixture in a combustion chamber includes a rotational speed Ne detection device for detecting the rotational speed Ne of the two cycle engine and for generating a rotational speed Ne signal. An opening .THETA. detection device is provided for detecting the opening .THETA. of a throttle provided in an intake passage for regulating the supply of air and for generating an opening .THETA. signal. A basic injection quantity setting device is provided for setting a basis injection quantity of the fuel based on the rotational speed, Ne signal and the opening .THETA. signal.

Abstract: A fuel injection controlling device for a two-cycle engine includes an electronic fuel injection system having a fuel injection quantity determining device for determining a fuel injection amount in response to rotational speed and throttle opening of the engine. At engine start, the controlling device, in response to operation of an engine kick starter, sequentially decreases starting fuel amount as the number of actuations of the kick starter increases. Fuel injection amount is also decreased in response to increasing engine temperature.

Abstract: A fuel injection controlling device for a two-cycle engine includes an electronic fuel injection system having a fuel injection quantity determining device for determining a fuel injection amount in response to a rotational speed of said engine and a throttle opening. A misfire detecting device is provided for detecting a misfire condition of said engine. Further, a device is provided for decreasing the amount of fuel injection upon transition from a misfire condition to a fired condition. The misfire detecting device includes a sensor for detecting an internal pressure of an intake air path, a storage device for storing therein an output value of the sensor and data of an intake air path internal pressure in a predetermined operating condition of the engine upon normal combustion, and a comparison device for comparing the output value with data read out from the storage means to detect a difference in pressure.