A vehicle has an engine, a CVT and at least one ground engaging member. A method of controlling the engine includes the steps of: determining an idle speed set point based at least in part on a first speed proportional to a driven pulley speed, the idle speed set point being less than an engagement speed when the driven pulley speed is less than a predetermined driven pulley speed and being less than an actual engine speed when the driven pulley speed is greater than the predetermined driven pulley speed; and controlling the engine to operate under conditions corresponding to the idle speed set point when a desired engine speed is less than the idle speed set point. Controlling the engine to operate under conditions corresponding to the idle speed set point causes engine braking when the driven pulley speed is greater than the predetermined driven pulley speed.

A device for measuring temperature of a turbine wheel in a turbocharger includes: a guide that passes infrared ray generated from the turbine wheel and includes a coolant path; a protection unit that protects an optical head which senses the infrared ray; and a signal processing unit that measures a temperature of the turbine wheel by processing a signal corresponding to the sensed infrared ray.

In a fuel injection controller, a first throttle opening TH0 is defined at a specific time P2. The P2 is a specific time later than the peak value of an intake pipe internal pressure PB of a previous cycle. In the cycle, P3 is a specific time that is set immediately before the calculation of the injection time. A second throttle opening TH2 is defined at P3. The fuel injection controller corrects a fuel injection amount based on variation in correction time ta0 at the first throttle opening TH0 to correction time ta1 at the second throttle opening TH1. The time P2 is later than time P1, which is the peak value of the intake pipe internal pressure of the previous cycle. Accordingly, the fuel injection amount correction is completely unaffected or only slightly affected by the intake pipe internal pressure, thus ensuring close-to-ideal correction.

Methods and systems are provided for opportunistically conducting an evaporative emissions test diagnostic procedure in order to indicate the presence or absence of undesired evaporative emissions in a vehicle evaporative emissions control system and fuel system. In one example, tire pressure and barometric pressure are monitored, and responsive to a tire pressure decrease in the absence of a barometric pressure increase, along with an indication that the vehicle transmission is in neutral and that the vehicle is not traveling downhill, the evaporative emissions system and fuel system may be sealed and the presence or absence of undesired evaporative emissions indicated based on a vacuum-build. In this way, an opportunistic evaporative emissions test may be conducted based on conditions favorable to conducting an emissions test procedure, and may thus increase test completion rates and reduce undesired evaporative emissions.

A handheld engine-driven working machine comprises an internal combustion engine with a throttle valve, a throttle adjusting device for adjusting an opening degree of the throttle valve of the internal combustion engine, and a control device provided in the internal combustion engine. The control device is configured to detect a rotational speed and an amount of change in the rotational speed at every at least one rotation of the internal combustion engine. The control device determines that the throttle valve is partially opened when the amount of change in the rotational speed is greater than a predetermined value.

Methods and systems are provided for operating a cylinder of an engine including a pre-chamber ignition system during a cold start condition. In one example, a method may include performing a post-injection in the cylinder, and then performing a pre-chamber combustion during an exhaust stroke of the cylinder. In this way, a temperature of a catalyst of the engine may be increased, which may decrease vehicle emissions during the cold start condition.

A straddle-type vehicle comprises a supercharging device which compresses intake-air to be sent to a combustion chamber of an engine; a catalyst provided in an exhaust passage through which an exhaust gas emitted from the engine flows; and a control section which controls the engine, wherein the control section performs an increase suppressing control for suppressing an increase in an exhaust gas temperature, in a case where the control section estimates that the exhaust gas temperature has exceeded an increase suppressing temperature set to be equal to or lower than a catalyst permissible temperature.

A method for controlling a forced induction engine includes: determining a first air pressure upstream of an air compressor, the air compressor supplying compressed air to the engine; determining a second air pressure downstream of the air compressor; determining a limit air flow rate to the engine corresponding to the surge limit of the air compressor based at least in part on the first and second air pressures; and controlling a throttle valve actuator to position the throttle valve at a position providing an air flow rate that is greater than or equal to the limit air flow rate. A vehicle power pack having a control unit implementing the method and a vehicle having the vehicle power pack are also disclosed.

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.

A dual compressor turbocharger includes two compressors. One compressor supplies fuel pressure, and one compressor supplies air pressure. The dual compressor turbocharger includes a turbine driven by exhaust of an engine and a shaft coupled to the turbine. The first compressor is mounted on the shaft and includes a first inlet coupled to an air supply and a first outlet coupled to an air intake of the engine. The second compressor is mounted on the shaft and includes a second inlet coupled to a fuel supply and a second outlet coupled to a fuel supply rail of the engine.