A control apparatus for an internal combustion engine includes circuitry configured to control a fuel injector of the internal combustion engine to stop injecting fuel to reduce torque generated by the internal combustion engine during upshift. The circuitry is to acquire a target injection amount parameter corresponding to a target injection amount of the fuel to be injected by the fuel injector to operate the internal combustion engine based on an operation state parameter corresponding to an operation state of the internal combustion engine. The circuitry is to acquire a minimum injectable amount parameter corresponding to a minimum injectable amount of the fuel injectable from the fuel injector. The circuitry is to control the fuel injector to start injecting the fuel when the minimum injectable amount parameter exceeds the target injection amount parameter while the fuel injector is controlled to stop injecting the fuel during the upshift.

Systems and methods for improving engine torque response are presented. In one example, engine idle speed is increased to shorten engine torque response based on engine operating conditions. The methods and systems may be useful for operating an engine that is supplied a gaseous fuel.

An engine system is mounted on a vehicle and includes an engine and a turbocharger. The engine system control apparatus includes: a driving state identifier that identifies a driving state of the vehicle from a plurality of driving states; a surge determiner that determines whether a surge condition as a condition under which a surge noise is generated is satisfied, based on the identified driving state of the vehicle and an operating state of the engine; and a variable nozzle controller that controls, based on the identified driving state of the vehicle and the operating state of the engine, an opening degree of a variable nozzle of the turbocharger to be varied in an open direction, upon determination by the surge determiner that the surge condition is satisfied.

A method for propulsion of a vehicle (100) having a combustion engine (101) and a gearbox (103), the engine (101) having a combustion chamber with an inlet for supply of combustion gas and an outlet for evacuation of exhaust gas, the method includes, during a change of gear from a first higher to a second lower gear ratio, increasing the pressure (P.sub.ut) at the chamber outlet (202) with a turbocharger unit and, when the rate of revolution (n) of the combustion engine (101) has at least partially fallen, controlling the turbocharger unit (203) such that the combustion gas pressure (P.sub.in) is increased.

A method for propulsion of a vehicle (100): The vehicle (100) includes a combustion engine (101), and a gearbox (103) that can be adjusted to a number of gear ratios for transfer of force between the combustion engine (101) and at least one driving wheel (113, 114), at least one combustion chamber with at least one inlet for the supply of combustion gas and at least one outlet for the evacuation of an exhaust gas flow that has resulted from combustion in the combustion chambers and a turbocharger unit (203) for pressurizing the combustion gas. In the method, during the change of gear from a first higher gear ratio to a second lower gear ratio, the rate of revolution of the combustion engine (101) is reduced, to control the turbocharger unit such that the pressure of the combustion gas is reduced, to increase the pressure at the outlet by constriction of the exhaust gas flow, and when the rate of revolution of the combustion engine (101) has at least partially fallen towards a second rate of revolution, to control the turbocharger unit such that the combustion gas pressure is increased. Also a system and a vehicle including the system.

A target reaching rotational speed set during a torque phase is set to a value higher than an actual engine rotational speed, the value being higher as one of a vehicle acceleration and an engine rotational speed gradient is larger. That is, as the acceleration is steeper, the target reaching rotational speed is set to a value closer to an upper limit rotational speed or rotational speeds proximate thereto. Thus, a display rotational speed displayed on a tachometer at the end of the torque phase becomes high rotational speed. Accordingly, there is provided a display control device for a vehicle that enables a driver to feel the use of engine performance to the limit.

Methods and systems are presented for assessing the presence or absence of engine torque deviation which may indicate air-fuel ratio imbalance between engine cylinders. In one example, the method may include assessing the presence or absence of engine torque variation based on engine torque deviation from a desired engine torque during a deceleration fuel shut-off event.

The engine control device comprises a basic target torque-deciding part for deciding a basic target torque based on a driving state of a vehicle, a torque reduction amount-deciding part for deciding a torque reduction amount based on a steering wheel operation state, an TCM for deciding a torque-down demand amount, based on a driving state of the vehicle other than the steering wheel operation state, and a final target torque-deciding part for deciding a final target torque, based on the decided basic target torque, the decided torque reduction amount and the decided torque-down demand amount, wherein the final target torque-deciding part is operable, when there is a torque-down demand, to restrict a change in the final target torque corresponding to a change in the torque reduction amount.

A multipurpose vehicle includes an engine, a fuel supply unit that supplies fuel to the engine, a gear transmission device that changes speed of power from the engine through a shifting operation, a coupling state detection sensor that detects a coupling state of the gear transmission device, a determination unit that determines whether the coupling state is an incomplete coupling state based on a detection signal from the coupling state detection sensor, and a fuel supply control unit that executes a fuel cut to reduce a fuel supply amount of the fuel from the fuel supply unit to the engine to a value less than a reference value, if the determination unit determines that the coupling state is the incomplete coupling state.

An electromagnetic control valve normality determination system includes: a hydraulic pressure source; an electromagnetic control valve structured to regulate an actual pressure of oil to a pressure command point, wherein the oil is supplied from the hydraulic pressure source; and an actual pressure sensor structured to sense the actual pressure of the oil. For determining normality of pressure regulation of the electromagnetic control valve, a normality determinator is configured to: set pressure command regions for determination about pressure regulation of the electromagnetic control valve, without overlapping among the pressure command regions; determine for each of the pressure command regions whether a difference between the actual pressure and the pressure command point in the each of the pressure command regions is less than a threshold value; and determine that the electromagnetic control valve is normal, in response to affirmation of the determination for all of the pressure command regions.