Methods and systems are provided for estimating exhaust gas recirculation (EGR) flow in an engine including an EGR system. In one example, a method may include operating the EGR system in an open loop feed forward mode based on an intake carbon di oxide sensor output above a threshold engine load and/or when a manifold absolute pressure (MAP) is above a threshold pressure, and operating the EGR system in a closed loop feedback mode based on a differential pressure sensor output when the engine load decreases below the threshold load and/or when the MAP decreases below the threshold pressure.

Methods and systems are provided for estimating exhaust gas recirculation (EGR) flow in an engine including an EGR system. In one example, a method may include operating the EGR system in an open loop feed forward mode based on an intake carbon di oxide sensor output above a threshold engine load and/or when a manifold absolute pressure (MAP) is above a threshold pressure, and operating the EGR system in a closed loop feedback mode based on a differential pressure sensor output when the engine load decreases below the threshold load and/or when the MAP decreases below the threshold pressure.

An internal combustion engine for driving a working assembly with a clutch, including a combustion chamber into which a mixture of fuel and air is supplied, a spark plug to ignite the mixture, ignition of the mixture driving a piston operably coupled to a crank portion of the engine, a fuel supply system including a fuel valve and a throttle valve, a throttle position sensor configured to determine a position of the throttle valve, a speed sensor configured to determine engine speed, and an electronic control unit configured to control operation of the fuel valve and the spark plug, the electronic control unit being configured to initiate a speed limitation operation in response to a first position of the throttle valve at engine start-up, wherein the speed limitation operation continues until the throttle valve is moved from its first position.

Methods and systems are provided for restarting an engine following an engine idle-stop. In one example, a method may include, prior to an engine restart following an idle-stop, adjusting a spark ignition timing based on an estimation of a fuel-air equivalence ratio (phi) and an estimation of a cylinder turbulence. Optimal spark ignition timing based on estimated phi and cylinder turbulence during engine restart may result in stabilized combustion and a torque output sufficient to at least partially relieve demand on the starting device.

Methods and systems are provided for restarting an engine following an engine idle-stop. In one example, a method may include, prior to an engine restart following an idle-stop, adjusting a spark ignition timing based on an estimation of a fuel-air equivalence ratio (phi) and an estimation of a cylinder turbulence. Optimal spark ignition timing based on estimated phi and cylinder turbulence during engine restart may result in stabilized combustion and a torque output sufficient to at least partially relieve demand on the starting device.

In a catalyst warming-up control, a first time injection is performed by an injector in an intake stroke. A second time injection is performed with an amount smaller than the first time injection in an expansion stroke after a compression top dead center. In the catalyst warming-up control, an interval from the start of the ignition period of an spark plug to the completion of the second time injection is controlled by the ECU so that the initial flame generated from an air-fuel mixture containing the fuel spray injected by the first time injection is brought into contact with the fuel spray injected by the second time injection.

In a catalyst warming-up control, a first time injection is performed by an injector in an intake stroke. A second time injection is performed with an amount smaller than the first time injection in an expansion stroke after a compression top dead center. In the catalyst warming-up control, an interval from the start of the ignition period of an spark plug to the completion of the second time injection is controlled by the ECU so that the initial flame generated from an air-fuel mixture containing the fuel spray injected by the first time injection is brought into contact with the fuel spray injected by the second time injection.

An ignition coil unit includes: an ignition circuit including a primary coil and a secondary coil; a power generator including a generator coil; a controller configured to control an ignition timing of the ignition circuit by an input signal generated by an induced voltage of the generator coil; and a sensor configured to input load information to the controller. The controller includes a memory configured to store working time information which corresponds to operating information based on the input information and the load information, as matrix data composed of the operating information, the load information and time data.

A standby generator includes a standby housing defining a cavity and an internal combustion engine. The engine includes an engine block including a cylinder comprising a piston, an engine housing at least partially covering the engine block, and a crankshaft configured to rotate about a vertical crankshaft axis in response to movement by the piston. The standby generator also includes an alternator configured to generate alternating current electrical power, a controller comprising a rectifier configured to convert the alternating current to a direct current and an inverter configured to convert the direct current to a clean alternating current electrical power, and a transfer switch configured to receive the clean alternating current electrical power from the controller and at least one of grid, solar, or battery power, and configured to supply power to an electrical load. The internal combustion engine, the alternator, and the controller are positioned within the cavity.

An electronic control unit of an internal combustion engine is configured to, when cooling fuel is supplied to a combustion chamber, calculate a target amount of supply of the cooling fuel and calculate a first upper limit injection amount that is an upper limit of an amount of fuel allowed to be injected from a second valve as the cooling fuel, when the target amount of supply is less than or equal to the first upper limit injection amount, supply the cooling fuel in the entire target amount of supply from the second valve to the combustion chamber in a first mode in which single-stage injection is performed, and, when the target amount of supply is greater than the first upper limit injection amount, supply the cooling fuel to the combustion chamber in a second mode in which the cooling fuel more easily diffuses than in the first mode.