Abstract: A control device for an internal combustion engine performs rich control when a fuel cutoff operation is terminated and fuel supply to a combustion chamber is restarted, and the engine includes a plurality of the combustion chambers and a fuel supply cycle is repeated. The control device includes a controller configured to set a first moment and a second moment such that the fuel supply cycle which includes the first moment is different from the fuel supply cycle which includes the second moment, the first moment being a moment at which the rich control is started in a first combustion chamber of the plurality of combustion chambers, and the second moment being a moment at which the rich control is started in a second combustion chamber of the plurality of combustion chambers that is different from the first combustion chamber.

Abstract: An engine having two or more fuel injectors is disclosed, where at least one of the injectors is used to port fuel inject fuel into the cylinder when the air intake valve is open. The open valve port fuel injector is used to inject a fuel that has alcohol as a constituent and is the same fuel injected by another fuel injector. In other embodiments, the open valve fuel injector is used to inject an anti-knock fuel containing alcohol while a primary fuel, is introduced by another injector. The operation of the open valve fuel injector can be optimized to maximize the vaporization cooling. In other embodiments, the open valve fuel injector may be used in conjunction with direct injection of the primary fuel or the anti-knock fuel. Heavy EGR can be optimally used with the various embodiments.

Abstract: A method for operating an internal combustion engine, having an exhaust gas turbocharger, during a load change of the internal combustion engine, includes initiation of a closing process of a throttle valve of the internal combustion engine, disposed in an induction tract or intake section of the internal combustion engine, as a function of an air pressure which is present upstream of the throttle valve, in such a way that the air pressure always falls short of a surge limit or pumping limit of a compressor, disposed in the induction tract, of the exhaust gas turbocharger. A staged or stepped reduction in a torque of the internal combustion engine is performed by shutting off fuel injections at predetermined cylinders of the internal combustion engine. An internal combustion engine with an exhaust gas turbocharger is also provided.

Abstract: An inter-cylinder air-fuel ratio imbalance determining apparatus for an internal combustion engine includes an air-fuel ratio sensor; fuel injection valves; an instructed fuel injection amount control unit; and an imbalance determination unit configured: to acquire a time-differential-value corresponding value that is an amount of change per predetermined time in an output value of the sensor or a detected air-fuel ratio represented by the output value; to acquire a positive gradient corresponding value based on a positive value of the time-differential-value corresponding value; to acquire a negative gradient corresponding value based on a negative value of the time-differential-value corresponding value; to determine an imbalance determination threshold based on a magnitude of a ratio of the negative gradient corresponding value to the positive gradient corresponding value; and to determine whether inter-cylinder air-fuel ratio imbalance has occurred by comparing a magnitude of the negative gradient corresp

Abstract: A geometric compression ratio in an engine main body 1 is set to 15 or less. Injection control means (ECU 40) performs a main injection of injecting fuel near a compression top dead center, and a preceding injection prior to the main injection at a specific region of predetermined load within an operating region on a relatively low-speed side. The injection control means performs, as the preceding injection, a pilot injection of performing injection at a timing such that at least part of a fuel spray reaches outside a cavity 31 on a top face of a piston, and a pre-injection of injecting fuel at a predetermined timing after the pilot injection, to suppress thereby ignition of the fuel injected by the pilot injection and shorten an ignition delay of the fuel injected by the main injection.

Abstract: Methods and systems are provided for controlling a vehicle engine to reduce cycle-to-cycle combustion variation. A predictive model is applied to predict cycle-to-cycle combustion behaviour of an engine based on observed engine performance variables. Conditions are identified, based on the predicted cycle-to-cycle combustion behaviour, that indicate high cycle-to-cycle combustion variation. Corrective measures are then applied to prevent the predicted high cycle-to-cycle combustion variation.

Abstract: An inter-cylinder air-fuel ratio imbalance determination apparatus that obtains, based on an output value Vabyfs of an air-fuel ratio sensor, an air-fuel ratio fluctuation indicating amount (AFD) which becomes larger as an air-fuel ratio fluctuation of an exhaust gas passing through a position at which the air-fuel ratio sensor is disposed becomes larger, during a parameter obtaining period. The determination apparatus estimates an air-fuel ratio sensor element temperature (Temps) having a strong relation with responsiveness of the air-fuel ratio sensor during the parameter obtaining period, and obtains a corrected air-fuel ratio fluctuation indicating amount by correcting the AFD based on the estimated Temps.

Abstract: A modification to the “gas-topping” invention disclosed in WO 2008/064415 is disclosed in this specification. The modification involves measuring a sensor input such as that provided by a diesel engine diesel fuel rail pressure sensor (5) to thereby provide a signal indicative of fuel flow rate, modifying that signal by a signal modifier (3), and substituting the modified signal for the original unmodified signal in an engine electronic control unit (7). The result is that there is no increase in engine power relative to that produced without “gas-topping” so that substantially all the benefits of “gas-topping” are captured in decreased fuel consumption and not to provided in the form of increased engine power.

Abstract: A fuel injection control for an internal combustion engine is performed. A fuel injection start timing from a first fuel injection valve placed in one intake port branching off for each cylinder is set to introduce a spray of fuel into the cylinder at the timing of introducing intake air into the cylinder, and a start timing of fuel injection from a second fuel injection valve placed in the other branching intake port is set in synchronization with the completion of injection of the first fuel injection valve, to start fuel injections from the first fuel injection valve and the second fuel injection valve at these set injection start timings. Accordingly, mixing performance of a spray of fuel and air is increased, and thus, enabling improvements in drivability during deceleration (torque shock), fuel economy, and exhaust emissions.

Abstract: A method comprises steps for reconstructing in-cylinder pressure data from a vibration signal collected from a vibration sensor mounted on an engine component where it can generate a signal with a high signal-to-noise ratio, and correcting the vibration signal for errors introduced by vibration signal charge decay and sensor sensitivity. The correction factors are determined as a function of estimated motoring pressure and the measured vibration signal itself with each of these being associated with the same engine cycle. Accordingly, the method corrects for charge decay and changes in sensor sensitivity responsive to different engine conditions to allow greater accuracy in the reconstructed in-cylinder pressure data.

Abstract: An abnormal combustion detection apparatus detects an abnormal combustion of an internal combustion based on a vibration waveform from a vibration sensor attached to the internal combustion engine. A gain circuit of the apparatus amplifies or attenuates the vibration waveform from the vibration sensor, an AD conversion circuit converts a waveform provided by the gain circuit to digital data, and a gain switching unit switches a gain of the gain circuit from a small gain value to a large gain value at a gain switch timing. The gain switching unit separates a large abnormal combustion from a small abnormal combustion in an abnormal combustion determination period for maximizing a dynamic range of an AD conversion circuit and for securely detecting a change of waveform amplitude in case of gain switching in an abnormal combustion detection operation.

Abstract: A gaseous fuel control system for a dual-fuel internal combustion engine comprising a plurality of valves for controlling the amount of gaseous fuel supplied to the engine. The valves have adjustable full-open flow rates and rapidly move from full-open to full-closed in response to a digital signal. An electronic system for monitoring at least one engine operating parameter maps the parameter value to control the opening and closing of the valves to establish a desired gaseous fuel flow rate.

Abstract: A fuel injection controller includes an output detecting portion detecting a first output generated by a combustion of a fuel which a sensor-injector injects and a second output generated by a combustion of a fuel which the second fuel injector injects, a first injection quantity computing portion computing, based on a detection value of the fuel pressure sensor, a first injection quantity injected by the sensor-injector injector to generate the first output, and a second injection quantity estimating portion estimating a second injection quantity injected by the second fuel injector to generate the second output, based on the first output, the second output and the first injection quantity.

Abstract: A method for regulating HCCI combustion of fuel in a reactor of an internal combustion engine is described in which a multivariable regulation is used, manipulated variable changes ?uk for the instantaneous regulating cycle k being determined on the basis of at least system deviations ?xk-1 and manipulated variable changes ?uk-1 of a preceding regulating cycle k?1.

Abstract: This invention relates to a deposit remove amount estimation device for estimating inlet and outlet deposit remove amounts by calculating an inlet deposit remove amount which is an amount of a removed combustion product among the combustion product accumulating on an injection hole inlet area and an outlet deposit remove amount which is an amount of a removed combustion product among the combustion product accumulating on an injection hole outlet area. In this invention, the inlet deposit remove amount is calculated on the basis of the inlet deposit accumulation amount which is an amount of the combustion product accumulating on the injection hole inlet area and the outlet deposit remove amount is calculated on the basis of the outlet deposit accumulation amount which is an amount of the combustion product accumulating on the injection hole outlet area.

Abstract: An engine system may include a fuel and air supply circuit and an exhaust circuit, a temperature sensor mounted on an exterior of the engine and an oxygen sensor located in the exhaust circuit. The fuel and air supply circuit may include a throttle body mounted on the engine and having a throttle valve to control the flow rate of air delivered to the engine, a fuel injector carried by the throttle body to deliver fuel to the engine and a fuel rail carried by at least one of the throttle body and the fuel injector and having an input to receive a supply of fuel and an outlet through which fuel is routed to the fuel injector. An engine control unit may be communicated with these components to control the fuel and air mixture provided to the engine as a function of the temperature and oxygen sensor outputs.

Abstract: A control device for an internal combustion engine, which determines a fuel injection quantity deviation state and/or an intake oxygen concentration-related parameter deviation state on the basis of the relationship between the target value (Qtgt) of the fuel injection quantity and an NOx concentration deviation (?NOx) indicating the difference of the measured value or the estimate value of the NOx concentration of exhaust gas with respect to a predetermined NOx reference concentration, the control device having a state determination means for, on the basis of a first determination index including the amount of change of the NOx concentration deviation (?NOx) when the target value (Qtgt) of the fuel injection quantity increases within a predetermined range and the NOx concentration deviation (?NOx) when the target value (Qtgt) of the fuel injection quantity is a predetermined first value (Qtgt2), determining whether the fuel injection quantity deviation is zero, positive, or negative.

Abstract: An injection valve injects a given amount of fuel into an engine in response to an injection pulse. An ECU inputs the injection pulse corresponding to an amount of injected fuel. The ECU inputs information on an amount of injected fuel corresponding to the number of injection pulses to a display controlling portion through a communication line. The ECU produces the information on the amount of injected fuel composed of digital data whenever a given number of injection pulses corresponds to the given amount of fuel. The display controlling portion decides that the given amount of fuel is injected from the injection valve when a predetermined number of pieces of digital data are properly received. The display controlling portion calculates an instantaneous fuel consumption based on an amount of injected fuel thus decided and an operating distance to cause a meter to display information on the instantaneous fuel consumption.

Abstract: A control system for a combustion system is applied to a combustion system which has a fuel injector injecting a fuel directly into a combustion chamber and a water injector injecting water (non-combustible fluid) into the combustion chamber. When a combustion engine operates at high load, the water collides with a fuel spray which the fuel injector injects. When a combustion engine operates at low-load, the water injection starts before the fuel injection and the water injection terminates before the fuel injection starts. Thus, the misfire can be avoided and NOx can be decreased by water injection at low-load operation of a combustion engine.

Abstract: An injection valve includes a nozzle needle that suppresses a metered addition of fluid in a closed position and otherwise allows the metered addition of fluid. The valve includes a control chamber hydraulically coupled to the nozzle needle such that the fluid pressure of the chamber influences the nozzle needle position. The pressure of the chamber can be influenced by a control valve having a control valve body. The injection valve includes a solid state actuator that acts on the control valve body. To perform a closing operation of the nozzle needle, the control valve body is controlled to the closed position by partially discharging the solid state actuator to a predetermined partial charge such that the actuator remains force-coupled to the control valve body even after the closed position of the control valve body has been reached. The actuator is used as a pressure sensor during the closing operation.

Abstract: A method for controlling combustion in a spark-ignition direct-injection internal combustion engine includes monitoring at least one combustion input parameter, and when the at least one monitored combustion input parameter deviates from a respective desired combustion input parameter, adjusting a combustion input mechanism associated with controlling the at least one monitored combustion input parameter to converge toward the respective desired combustion input parameter.

Abstract: A control device for an internal combustion engine which can highly precisely realize required torque including a high-frequency component with high responsiveness. The control device sets torque with a low frequency included in the required torque as an air quantity controlling torque, and calculates a target air quantity for realizing the air quantity controlling torque based on data in which a relationship of the air quantity and torque is set. The control device controls the air quantity in accordance with the target air quantity. Further, the control device sets torque including both a low frequency and a high frequency as air-fuel ratio controlling torque, and calculates an air-fuel ratio corresponding to the air-fuel ratio controlling torque and a present air quantity as a target air-fuel ratio. The control device controls a fuel injection amount in accordance with the target air-fuel ratio.

Abstract: A system according to the principles of the present disclosure includes a fuel mass module and a fuel control module. The fuel mass module determines a first fuel mass before the first fuel mass is injected into one of a cylinder of an engine and an injection port of the cylinder. The fuel mass module also determines a second fuel mass after injection of the first fuel mass starts. The fuel control module controls a first fuel injector to inject the first fuel mass into the one of the cylinder and the injection port for a combustion event. The fuel control module also controls a second fuel injector to inject the second fuel mass into one of the cylinder and the injection port for the combustion event. The second fuel injector is different from the first fuel injector.

Abstract: A control system for an engine includes a fuel mass determination module, a mass fraction determination module, and a fuel injector control module. The fuel mass determination module determines a first minimum fuel mass corresponding to a first fuel system of the engine. The mass fraction determination module determines first minimum and maximum mass fractions based on the first minimum fuel mass and a total fuel mass. The fuel injector control module limits a first desired mass fraction based on the first minimum and maximum mass fractions, and controls a first fuel injector of the engine based on the limited first desired mass fraction.

Abstract: Methods and systems are described for conserving fuel used by an engine. In some embodiments a control module processes a user-provided input, as a first function, into a second function. The second function can be used to direct the engine with a directive output power. The directive output power may have regions equal to, greater than, and/or less than what the power output would be if the engine were controlled using the user-provided input.

Abstract: When the internal combustion engine is in an injection-free operating mode, a selected injector is open for injecting a small fuel amount, whereby at least one working cycle with injector control follows or precedes one cycle without control, a differential of two subsequent segment times of the cylinder associated with the selected injector or another variable, that reproduces a temporal crankshaft angle speed modification, is determined as a measurement value respectively for the cycle with and without control, and a relation is formed between the values of the cycles with or without control and used to correct the injection characteristic curve. The engine operates with active ignition and the value for the cycle with control is tested by taking into account ignition faults and the relation is only used to correct the curve if the value in the cycle with control significantly deviates from the one without control.

Abstract: A control system of an internal combustion engine in which as fuel, a first fuel of ammonia and a second fuel easier to burn than ammonia are used. These two types of fuel are burned in the combustion chamber. A basic ammonia ratio is set in accordance with an engine load and engine speed. The set basic ammonia ratio is corrected based on at least one of a combustion state, knocking strength, temperature of an exhaust gas or temperature of a catalyst arranged in an engine exhaust passage, NOx concentration in the exhaust gas, actual compression ratio, air-fuel ratio, and fuel properties.

Abstract: A fuel control apparatus (100) for an internal combustion engine in a vehicle, the vehicle provided with: the internal combustion engine (200) provided with a fuel supply apparatus (208, 209) capable of supplying, as fuel, first fuel (liquid fuel) and second fuel (CNG) in which amount of a reducing agent in an exhaust air under an rich air-fuel ratio is greater than that in the first fuel; and an exhaust purification apparatus (300, 400) disposed in an exhaust passage of the internal combustion engine, the fuel control apparatus provided with: a first controlling device for controlling the fuel supply apparatus such that the supply of the fuel is temporarily stopped under a predetermined condition; and a second controlling device for controlling the fuel supply apparatus such that the second fuel is supplied as the fuel and such that an exhaust air-fuel ratio is the rich air-fuel ratio, if the supply of the fuel is restarted from a state in which the supply of the fuel is temporarily stopped.

Abstract: Various systems and methods are described for controlling fuel injection of a dual fuel engine which includes first and second fuel rails and first and second fuel pumps. In one example, while pumping is suspended in the second fuel rail, the first fuel is injected to all but one cylinder of the engine and the second fuel is injected to the one cylinder in a predetermined sequence. As such, the fuel injector injecting to the one cylinder is isolated and its performance may be assessed without significantly affecting engine performance.

Abstract: A method and system for controlling an engine includes a desired fuel mass determination module that determines fuel mass for injection into a cylinder. The system also includes a split determination module that splits the fuel mass into split fuel masses and a pulsewidth determination module that converts the split fuel masses into injection pulsewidths outside of an injector operation exclusion zone.

Abstract: A system for controlling fuel to an engine to minimize emissions in an exhaust of the engine. There may be a controller connected to an actuator, for example a fuel control actuator, of the engine and to emissions sensors, such as an NOx and/or PM sensor, proximate to an exhaust output of the engine. The controller, for example a speed controller, may have an input connected to an output of a pedal or desired speed setting mechanism. A speed sensor at a power output of the engine may be connected to an input of the controller.

Abstract: In an internal combustion engine (engine) in which premixed combustion and diffusion combustion are carried out in a combustion chamber, the premixed combustion and the diffusion combustion are separated by carrying out a control to limit the minimum value of the heat generation rate between the combustion centroid of the premixed combustion and the combustion centroid of the diffusion combustion, or carrying out a control to adjust the interval between a first injection for the premixed combustion and a second injection for the diffusion combustion. In this manner, the combustion form in the combustion chamber is made separated combustion in which the premixed combustion and the diffusion combustion are separated, and therefore ignition delay in the earlier premixed combustion does not influence the later diffusion combustion, thus making it possible to use the respective advantages of the premixed combustion and the diffusion combustion.

Abstract: A method for adapting the actual injection quantity of an injector of an internal combustion engine to the target injection quantity, an injection device for an internal combustion engine, and an internal combustion engine are provided. In the method, the crankshaft acceleration achieved by a test injection pulse is detected in the rotational speed signal of the internal combustion engine and on this basis the injected fuel quantity of the injector is determined. On the basis of the determined injected fuel quantity, the actuating data of the injector of the internal combustion engine is corrected. To this end, the injected fuel quantity of the injector is detected and corrected by a test injection pulse during the normal fired operational state of the internal combustion engine.

Abstract: Embodiments of the present invention include an engine control method for controlling an engine having an accessory. In the method, a relationship between a torque of the accessory and a controlled variable corresponding to each rotational speed of the engine is stored in advance. An estimated value of the controlled variable is calculated based on a calculated value of the torque of the accessory and the engine rotational speed by reference to the said relationship. A command value of the controlled variable is calculated based on at least one of the engine rotational speed, opening of a throttle, opening of an accelerator and an air supply pressure. A calculated difference is determined by comparing the estimated value of the controlled variable and the command value of the controlled variable.

Abstract: The present invention has an object to enable a torque as required to be realized without being influenced by an operation state of an IN-VVT, which is a variable valve timing mechanism which changes a valve timing of an intake valve. For this purpose, a control device for an internal combustion engine provided by the present invention stores data that defines a relationship between an air quantity and a torque in an MBT in association with the operation state of the IN-VVT, and calculates a target air quantity for realizing a required torque based on the data. The control device calculates an actual air quantity which is actually realized by an operation of a throttle when operating the throttle to realize the target air quantity.

Abstract: A closed-loop control algorithm that reduces the increases in nitrogen oxides (NOx) commonly observed with biodiesel combustion while retaining particulate matter (PM) reductions with variable biodiesel blend fractions. One embodiment includes a control algorithm that is closed-loop with regards to combustible oxygen mass fraction (COMF) instead of exhaust gas recirculation (EGR) fraction. Yet another algorithm includes biodiesel blend estimation and “fuel-flexible” accommodation. A physics-based model has also been developed which predicts experimentally observed engine performance and emissions for biodiesel.

Abstract: A control apparatus for an internal combustion engine where the inside of a combustion chamber is divided into a layer of internal EGR gas and a combustible layer to perform stratified combustion. In a port-injected engine equipped with first and second intake valves, the opening timing of the first intake valve is set before a top dead center (TDC) and the opening timing of the second intake valve is set after the TDC, and the closing timings of the first intake valve and the second intake valve are set after a bottom dead center. Then, fuel injection toward the first intake valve is started after the EGR gas, which was blown back to the intake port upstream of the first intake valve, is drawn into the combustion chamber after the top dead center.

Abstract: An engine includes a normal fuel tank, fuel gas tank, an in-tank injection valve and a fuel gas supply valve. During operation of the engine, in a state where the fuel gas supply valve is closed, a fuel is injected into the fuel gas tank through the in-tank injection valve to generate a fuel gas by vaporizing the fuel. The fuel gas is stored in the fuel gas tank and is maintained in the gas phase due to the natural decompression even after the engine is stopped. To start the engine, the fuel gas supply valve is opened to supply the fuel gas in the fuel gas tank to a surge tank. Thus, compared with the case where the fuel gas is generated at the start of the engine, the fuel gas can be quickly supplied into the cylinder, so that the ability to start the engine is improved.

Abstract: A PCV circuit for an internal combustion engine is modified to deliver the PCV fluid to an atomization chamber which also receives fuel from an electronic fuel injector tapped into the main vehicle fuel supply. The fuel from the injector is thoroughly vaporized in and/or immediately downstream of the chamber and conveyed to the vehicle intake manifold. In one embodiment, a switch cuts off operation of the fuel injector at high load/high throttle setting conditions. In another embodiment, injected fuel is measured with increased engine load. The injector operates at a constant frequency with a variable ON time.

Abstract: Methods and systems are provided for controlling exhaust emissions by adjusting a fuel injection into an engine cylinder from a plurality of fuel injectors based on the fuel type of the injected fuel and further based on the soot load of the engine. Soot generated from direct fuel injection is reduced by decreasing an amount of direct injection into a cylinder as the engine soot load increases.

Abstract: Engine surge includes oscillations in engine torque resulting in bucking or jerking motion of a vehicle that may degrade driver experience. The present application relates to increasing reformate entering an example engine cylinder in response to engine surge.

Abstract: An exhaust valve early-closure control brings about blowback of exhaust gas into an intake system. However, if the exhaust valve early-closure control is executed, for example, during a first idle operation immediately following the startup of the engine, or the like, the amount of blowback exhaust gas becomes excessively large. Therefore, when the post-startup increase amount has decreased to or below a lower-limit criterion value, the ECU prohibits the exhaust valve early-closure control, and changes the control to a usual valve timing control. As a result, during a period during which the combustion state has a stability margin and the amount of emission of HCs and the like is large, the exhaust emission quality can be bettered by the exhaust valve early-closure control. Besides, when the post-startup increase amount has decreased, the combustion state can be stabilized by prohibiting the exhaust valve early-closure control.

Abstract: An internal combustion engine (1) has a fuel tank (18) and a fuel vapor reservoir (25). According to the method during the tank vent period—before opening the tank vent valve (28) a reference value is updated if a condition is met, and otherwise the existing reference value is maintained, —before opening the tank vent valve (28) an opening period is determined as a function of at least one variable, —the tank vent valve (28) is controlled such that the flow achieves the target flow value by the end of the opening period that was determined, —the load level of the fuel vapor reservoir (25) is computed based on the reference value, —a fuel amount is computed based on the load level, —and the fuel amount to be metered by the injection valve (22) is corrected based on the computer fuel amount.

Abstract: An engine control system includes a power supply module, a measurement module, and a calibration module. The power supply module disables power supplied to N components of an engine when M cylinders of the engine are deactivated, wherein M and N are integers greater than or equal to one. The measurement module measures outputs of the N engine components. The calibration module calibrates the measurement module based on unpowered measurements from one or more of the N engine components during a period after the power supplied to the N components is disabled.

Abstract: A method of stoichiometrically operating a diesel-fueled internal combustion engine. During a main (conventional) fuel injection event, fuel is injected into the cylinders. The air-fuel ratio during this main fuel injection event is stoichiometric. The cylinders are operated by either advancing the exhaust valve closing or modifying the phasing of the exhaust and intake valve lift events, to achieve a negative valve overlap period between the end of the exhaust phase and the beginning of the intake phase of the engine cycle. Fuel is injected into the cylinders during the negative valve overlap period, which results in highly reactive fuel and reduces ignition delay during the main fuel injection event.

Abstract: Methods and systems are provided for heating a catalyst during engine cold-start conditions. One example embodiment uses positive valve overlap to drive a boosted blow-through airflow through the cylinders of an engine. Fuel is injected with the blow-through airflow during the valve overlap, and also injected into engine cylinders outside the valve overlap. The catalyst is heated by the resulting exothermic reaction of the blow-through airflow with the combustion products and the injected fuel in the exhaust manifold.

Abstract: A method for controlling engine temperature of an engine with a wide dynamic range is disclosed. In one example, the derivative of an engine temperature is assessed by a controller. The controller may adjust engine actuators to limit engine temperature in response to the derivative.

Abstract: An internal combustion engine control apparatus includes a first period in which the target heater applied effective voltage is set to a first target voltage with which the temperature of an exhaust gas sensor becomes a target temperature at a time when the internal combustion engine is being operated; a second control period in which after the automatic stop mode of the engine has started, the target heater applied effective voltage is set to a second target voltage lower than the first target voltage; and a third period in which after the second period, the target heater applied effective voltage is controlled to a third target voltage higher than the second target voltage and with which the temperature of an exhaust gas sensor becomes a target temperature at a time when the engine is in the automatic stop mode.

Abstract: Valve stopping control is performed that changes an operating state of an intake valve and an exhaust valve to a closed-valve stopped state when executing a fuel-cut operation. A device is provided that sets an in-cylinder return-time target air-fuel ratio for an initial two return cycles when returning from a fuel-cut operation. The return-time target air-fuel ratio is set so that respective air-fuel ratios of air-fuel mixtures of fuel and air injected into the same cylinder for respective cycles during the initial return cycles each become values that fall within a combustible range, and so that even if a total amount of fuel injected into the same cylinder for the initial return cycles is supplied into the cylinder during an arbitrary single cycle, the air-fuel ratio of the air-fuel mixture of the total amount of fuel and air becomes a value that falls within the combustible range.

Abstract: Over a diesel engine's lifetime, engine efficiency may be reduced and some of this may be attributable to sulfur deposit accumulation in the engine. A method for controlling operation of a diesel engine operating on a fuel is provided. The method may include adjusting an injection of fuel to the engine in response to a sulfur content of the fuel.