Methods and systems using model based and iterative calculations of mass flow throughout an internal combustion engine system. A secondary air injection valve is provided to selectively allow intake air to pass to the exhaust side of the engine system to aid in exothermic reaction with exhaust gasses exiting the engine for various purposes. The iterative calculations of mass flow include estimation of the mass flow through the secondary air injection valve.

An internal combustion engine operates so that it delivers zero or negative torque. The engine operates in either a deceleration cylinder cut off (DCCO) mode or skip cylinder compression braking mode. In the skip cylinder compression braking mode, selected working cycles of selected working chambers are operated in a compression release braking mode. Accordingly, individual working chambers are sometimes not fired and sometimes operated in the compression release braking mode while the engine is operating in the skip cylinder compression braking mode.

A straddled vehicle has a plurality of modes for engine brake controlling. The straddle vehicle includes a mode setter that selectively sets one of at least a normal mode and a first reduced mode that are included in the plurality of modes. An engine controller controls an electronic throttle valve and a fuel injector so that a torque of an internal combustion engine is equal to a target torque. When the torque of the internal combustion engine is less than zero while in the first reduced mode, an engine brake controller corrects the target torque by adding a first additive torque to the target torque. The first additive torque is set so as to be smaller as an amount of operation of an accelerator grip becomes larger so that an opening of the electronic throttle valve increases as the amount of operation of the accelerator grip increases.

An injection amount variation of a plurality of fuel injection valves is reduced regardless of a state of an engine. According to one aspect of the present invention, there is provided a fuel injection control device 127 that controls a plurality of fuel injection valves having a coil for energization, including a valve body operation time detection unit 211 that detects a valve closing completion time from an end of energization of the fuel injection valve to completion of valve closing of a valve body of the fuel injection valve, a drive current correction unit 213 that corrects a drive current parameter of the fuel injection valve based on the valve closing completion time, an injection pulse width correction unit 214 that corrects an energization time of the fuel injection valve based on the valve closing completion time, and a correction method selection unit 212 that selects at least one of the drive current correction unit 213 and the injection pulse width correction unit 214 to execute correction based on a state of an engine.

An integrated biomass conversion system and a method of starting and shutting down the system are disclosed. The integrated biomass conversion system comprises a syngas generator, such as a gasifier, a cleanup engine and a syngas utilization system, which could be a power producing engine or a chemical reactor for chemical or fuel synthesis. The cleanup engine operates rich and at high temperatures so that the tars exhausted by the syngas generators are destroyed and not allowed to foul other components. An orderly sequence to start and shut down the integrated biomass conversion system is disclosed.

Provided is a control device configured to be able to execute, in an engine which includes a DOC, a DPF, and a temperature increase unit including an exhaust throttle valve, for increasing a temperature of each of the DOC and the DPF, a forced regeneration process of removing PM deposited on the DPF by increasing the temperature of the DPF. The control device includes a flow rate estimation part configured to estimate an intake flow rate of a combustion gas sent into a cylinder of the engine. The flow rate estimation part is configured to estimate a first intake flow rate, which is the intake flow rate in the forced regeneration process, from an opening degree of the exhaust throttle valve and a first state amount which indicates an operation state of the engine including a rotation speed of the engine, based on a first relationship representing a relationship between the first intake flow rate, and the opening degree of the exhaust throttle valve and the first state amount, in the forced regeneration process.

A straddled vehicle engine unit including an internal combustion engine and a misfire detection device. The internal combustion engine has a crankshaft, and a crank angle signal output unit that periodically outputs a crank angle signal in accordance with rotation of the crankshaft. The internal combustion engine is configured to repeat at least two kinds of strokes on a cycle of every 720-degree rotation of the crankshaft. The misfire detection device includes a crankshaft rotation speed fluctuation physical quantity acquisition unit configured to acquire a physical quantity related to an amount of fluctuation in a rotation speed of the crankshaft in one kind of stroke, out of the at least two kinds of strokes, based on the crank angle signal from the crank angle signal output unit, and a misfire determination unit configured to perform a misfire determination in response to each acquisition of the crankshaft rotation speed fluctuation physical quantity.

A system and method of controlling a turbocharged engine system includes receiving a boost mode selection signal and controlling the turbocharged engine system in response to the boost mode selection signal.

A system includes a reciprocating piston engine configured to output torque to drive a load. The system includes an engine speed sensor operatively coupled with the engine and configured to output an engine speed signal. The system includes an electronic control system operatively coupled with the powertrain. The electronic control system is configured to determine an engine acceleration in response to the engine speed signal, and detect a misfire of the engine in response to the engine acceleration.

Methods and systems are provided for an engine. In one example, a method comprises stopping an engine via a soft-stop method in response to a likelihood of condensate forming being less than or equal to a threshold likelihood. The method further comprises stopping the engine via an exhaust gas evacuation method in response to the likelihood of condensate forming being greater than the threshold likelihood.