An engine is configured such that, during the starting of the engine, when it is being detected that throttle opening has been set at a starting position, if it is detected that the engine speed has exceeded a predetermined speed slightly lower than a speed when a centrifugal clutch becomes an engaged state, a control unit retards the ignition timing from a general angle to a first angle BTDC, and then advances the ignition timing to a second angle at predetermined intervals, and holds the ignition timing at the second angle for a predetermined time period, thereby preventing the engine from stopping due to fouling on the spark plug while suppressing the engine speed at the speed when the centrifugal clutch becomes the engaged state, or less.

There is provided a control device for an internal combustion engine including a variable-capacity turbocharger, which has a turbine with a variable nozzle and an actuator that controls the variable nozzle opening degree, and a throttle disposed in an intake passage. The control device includes an electronic control unit (ECU). The ECU include a first control mode as a control mode for the intake air amount. When an air amount range on the high flow rate side including a maximum value of a required air amount for the internal combustion engine is defined as a high air amount range, the ECU controls the actuator and the throttle so as to increase the throttle opening degree while maintaining the variable nozzle at a fully-closed opening degree as the required air amount is increased in the high air amount range on the side of the maximum value in the first control mode.

In an engine device, when executing normal control that performs fuel injection and ignition as control of an engine, a controller estimates, in the case of a stoichiometric air-fuel ratio, an exhaust gas temperature based on first thermal energy that is based on a combustion gas temperature, a combustion gas quantity, and specific heat of combustion gas, estimates, in the case of a lean air-fuel ratio, the exhaust gas temperature based on the first thermal energy and second thermal energy that is based on an air temperature, a surplus air quantity, and specific heat of air, and estimates, in the case of a rich air-fuel ratio, the exhaust gas temperature based on the first thermal energy and third thermal energy that is based on a fuel temperature, a surplus fuel quantity, specific heat of fuel, and evaporation latent heat of fuel.

A system includes an electronic fuel injection system of an engine, the electronic fuel injection system including an electronic governor control unit for controlling various functions of the engine.

Provided is an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Ignition timing of the preceding ignition is set to be more retarded when an in-cylinder pressure specified by an in-cylinder pressure specification section is high than when the in-cylinder pressure is low.

An engine controller, an engine control method, and memory medium are provided. A second calculation process calculates an intake air amount without using a detection result of an air flow meter. The determination process determines that intake air pulsation is great if it is confirmed that a difference between an average flow rate and a minimum flow rate is great. The average flow rate is an average value of an intake air flow rate within a period of the intake air pulsation. The minimum flow rate is a minimum value of the intake air flow rate within the period. When it is determined that the intake air pulsation is great, a calculation method switching process selects a calculated value of the intake air amount that is obtained by the second calculation process.

A method for controlling an internal combustion engine includes receiving a request for a desired output from the internal combustion engine, receiving sensor information indicative of at least an engine speed or a pressure of gas provided to the internal combustion engine, and setting a changeable limit associated with a supply of air and fuel to the internal combustion engine. The method also includes, based at least in part on the received sensor information, changing the changeable limit to define a changed limit and reducing an output of the internal combustion engine based on the changed limit.

In at least some implementations, a charge forming device includes a body that has a throttle bore, a throttle valve associated with the throttle bore, a coupler and an actuator. The throttle has a valve head received within and movable relative to the throttle bore, and a valve shaft to which the valve head is coupled. The coupler is connected to the valve shaft and carries or includes a sensor element. And the actuator has a drive shaft coupled to the coupler so that rotation of the drive shaft is transmitted to the coupler and the valve shaft.

A method for controlling a two-stroke engine operatively connected to a turbocharger, the turbocharger being in fluid communication with the engine to provide a boost pressure thereto, the method including: comparing one of (i) an actual power output of the engine; and (ii) an exhaust temperature representative of an actual temperature of exhaust gas being discharged by the engine, with a corresponding threshold value thereof; in response to the one of the actual power output of the engine and the exhaust temperature being less than the corresponding threshold value: determining a corrective amount of boost pressure to add to the boost pressure of the turbocharger; and controlling the turbocharger to increase the boost pressure of the turbocharger by the corrective amount. Another method for controlling a two-stroke engine operatively connected to a turbocharger is also disclosed.

A method for controlling an internal combustion engine includes receiving a request for a desired output from the internal combustion engine, receiving sensor information indicative of at least an engine speed or a pressure of gas provided to the internal combustion engine, and setting a changeable limit associated with a supply of air and fuel to the internal combustion engine. The method also includes, based at least in part on the received sensor information, changing the changeable limit to define a changed limit and reducing an output of the internal combustion engine based on the changed limit.