Abstract: In an in-cylinder injection spark-ignition internal combustion engine including a plurality of cylinders and a catalyst device disposed in an exhaust system of the engine, a fuel is injected to at least one selected cylinder selected from the plurality of cylinders to be operated, and subsequently the fuel is injected to all cylinders to be operated. At this time, a warm-up controlled variable for the at least one selected cylinder is smaller than the warm-up controlled variable used when all cylinders are operated. In the in-cylinder injection spark-ignition internal combustion engine, the all cylinder operation is started and the warm-up control is started for all cylinders to warm up the catalyst device disposed in the exhaust system of the engine preferably when a fuel injection pressure exceeds a target value.

Abstract: An engine control system in a vehicle including a variable displacement internal combustion engine, a speed sensor for detecting the speed of the variable displacement internal combustion engine, a controller for controlling the displacement of the variable displacement internal combustion engine, and where the controller varies the spark timing of the variable displacement engine based upon the detected speed during changes in the displacement of the variable displacement internal combustion engine.

Abstract: A method is disclosed for controlling operation of an engine coupled to an exhaust treatment catalyst. Under predetermined conditions, the method operates an engine with a first group of cylinders combusting a lean air/fuel mixture and a second group of cylinders pumping air only (i.e., without fuel injection). In addition, the engine control method also provides the following features in combination with the above-described split air/lean mode: idle speed control, sensor diagnostics, air/fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, default operation, and exhaust gas and emission control device temperature control. In addition, the engine control method also changes to combusting in all cylinders under preselected operating conditions such as fuel vapor purging, manifold vacuum control, and purging of stored oxidants in an emission control device.

Abstract: In a hybrid power output apparatus including an engine and a motor generator apparatus, a fuel supply stop process of stopping the supply of fuel is performed after performing a fuel increase process of increasing the amount of the fuel in a combustion chamber from that at a present state, as a control for preventing the deterioration of a catalyst upon stopping the engine. This makes it possible to prevent the catalyst from being exposed to a lean atmosphere.

Abstract: An engine control system including a variable displacement internal combustion engine, a plurality of cylinders located in the internal combustion engine, a plurality of fuel injectors for providing fuel to the plurality of cylinders, a plurality of valves coupled to the plurality of cylinders, the plurality of valves controlling the air flow in and out of the cylinders, an actuation apparatus for actuating the plurality of valves, an intake manifold coupled to the internal combustion engine, a throttle coupled to the intake manifold, a controller electronically coupled to the fuel injectors, an accelerator pedal position sensor electronically coupled to the controller, and where the controller determines the number of the cylinders to provide with fuel and air and a desired engine output torque based on the accelerator pedal position sensor and a hysteresis value.

Abstract: A control system for a multi-cylinder internal combustion engine is provided. The engine is of the kind in which switching between a full cylinder operation with all cylinders in operation and a part cylinder operation with some of cylinders kept out of operation is selectively performed. The control system comprises a first calculator for calculating, at the part cylinder operation, a target intake air fuel quantity per one operative cylinder that enables the engine to produce a torque equal to that at the full cylinder operation, a second calculator for calculating a throttle valve target opening area at the part cylinder operation from the target intake air quantity per one operative cylinder, and a controller for controlling a throttle valve opening degree so that the throttle valve target opening area is obtained. A control method is also provided.

Abstract: An idle stability control for a fuel injected internal combustion engine deactivates selected fuel injectors after specified idle conditions have been met for a predetermined period of time, and thereafter until the conditions are no longer met. The engine spark timing is temporarily modified on each transition to and from the control to reduce operator perception of the injector deactivation and reactivation. Additionally, the injector deactivation pattern is periodically adjusted following an overlap period during which all of the injectors are enabled.

Abstract: A method is disclosed for controlling operation of an engine coupled to an exhaust treatment catalyst. Under predetermined conditions, the method operates an engine with a first group of cylinders combusting a lean air/fuel mixture and a second group of cylinders pumping air only (i.e., without fuel injection). In addition, the engine control method also provides the following features in combination with the above-described split air/lean mode: idle speed control, sensor diagnostics, air/fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, default operation, and exhaust gas and emission control device temperature control. In addition, the engine control method also changes to combusting in all cylinders under preselected operating conditions such as fuel vapor purging, manifold vacuum control, and purging of stored oxidants in an emission control device.

Abstract: In a hydraulic pressure control system for an engine cylinder cutoff device through which a first group of cylinders are cut off with at least intake valves of engine valves included in the first group kept inactive, while a second group of cylinders are working, the system includes a valve mode switching mechanism being responsive to supply oil pressure for switching an operating mode of at least an intake valve of engine valves of each of the first group of engine cylinders from active to inactive. Also provided is a hydraulic pressure control valve regulating the supply oil pressure. A control unit incorporated in the system sets the supply oil pressure to a predetermined maximum pressure when initiating the inactive mode, and holds the supply oil pressure at a predetermined oil pressure lower than the predetermined maximum pressure before the inactive mode is released.

Abstract: In an assist control apparatus for a hybrid vehicle comprising an engine as a drive source of the vehicle, and a motor assisting drive of the engine in accordance with driving conditions of the vehicle, the engine is a cylinder deactivating engine switchable between a normal operation and a cylinder deactivating operation, and there is provided a cylinder resumption assist judgment device which judges whether the drive of the engine should be assisted by the motor, when the engine shifts from the cylinder deactivating operation to the normal operation, and when the cylinder resumption assist judgment device judges a resumption from the cylinder deactivated condition, and judges that a throttle opening is larger than a predetermined value, drive of the engine is assisted by the motor.

Abstract: A multi-cylinder internal combustion engine is described in which each cylinder is capable of operating within a predetermined auto-ignition torque/speed range. Selected cylinders are disabled when the average cylinder torque lies below the auto-ignition torque/speed range so as to raise the torque of the remaining power producing cylinders and enable them to continue to operate within the auto-ignition torque/speed range.

Abstract: A multi-cylinder internal combustion engine is described in which each cylinder is capable of operating within a predetermined auto-ignition torque/speed range. Selected cylinders are disabled when the average cylinder torque lies below the auto-ignition torque/speed range so as to raise the torque of the remaining power producing cylinders and enable them to continue to operate within the auto-ignition torque/speed range.

Abstract: The invention concerns a method for operating an internal combustion engine (1, 18) having a plurality of combustion chambers (4), in the case of which the combustion chambers (4) are charged with fuel and air or with a fuel/air mixture. In order to prevent torque jumps from occurring when cylinders (3) of the internal combustion engine (1, 18) are shut down and when switching the operating mode of direct-injection internal combustion engines (18), it is proposed that the charging of the combustion chambers (4) with fuel and air or with a fuel/air mixture be controlled individually via open-loop or closed-loop control for each combustion chamber (4). In the case of a direct-injection internal combustion engine (18), a certain number of combustion chambers (4) can be operated with homogenous-charge operation, and the remaining combustion chambers (4) can be operated with stratified-charge operation in accordance with the level of torque required.

Abstract: A vehicle engine control system controls an engine that includes a plurality of cylinders and that generates exhaust gas. An air-assisted direct injection fuel system supplies an air/fuel mixture to the cylinders. A catalytic converter reduces harmful emissions from the exhaust gas after the catalytic converter reaches a light-off temperature. A controller communicates with the engine, the catalytic converter and the air-assisted direct injection fuel system. The controller optimizes cam phasing, the air/fuel mixture and spark angle for full and partial engine operating modes. The controller deactivates at least one of the cylinders of the engine before the catalytic converter achieves the light-off temperature to hasten light-off of the catalytic converter.

Abstract: A method for operating a homogeneous-charge-compression-ignition (HCCI) engine at low speed includes the steps of monitoring the operating speed and load of the HCCI engine in a stable combustion condition. When the engine cylinder load drops below a predetermined value equal to the lowest allowed load at its current engine speed, at least one cylinder is deactivated to maintain the stable combustion in the remaining activated cylinders. When the cylinder load exceeds another predetermined value at its current engine operating speed, the cylinder is reactivated.

Abstract: A water-cooled multi-cylinder engine, includes a control system in which an engine revolution number is reduced to a level less than a restriction revolution number on the basis of at least one condition of misfire and fuel stop for all the cylinders of the engine, at a time of an occurrence of an overheat, so as to restrict an increasing of a temperature of the engine. In a case when the engine revolution number is less than the restriction revolution number after the overheat occurs, or the engine revolution number is lowered to be less than the restriction revolution number on the basis of the revolution number restriction control, a specific cylinder is controlled to be stopped by at least one of misfire and fuel stop.

Abstract: A method is disclosed for controlling operation of a engine coupled to an exhaust treatment catalyst. Under predetermined conditions, the method operates an engine with a first group of cylinders combusting a lean air-fuel mixture and a second group of cylinders pumping air only (i.e. without fuel injection.) In addition, the engine control method also provides the following features in combination with the above-described split air/lean mode: auto speed control, sensor diagnostics, air-fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, and default operation. In addition, the engine control method also disables the split air/lean operating mode under preselected operating conditions.

Abstract: A method is disclosed for controlling operation of an engine coupled to an exhaust treatment catalyst. Under predetermined conditions, the method operates an engine with a first group of cylinders combusting a lean air/fuel mixture and a second group of cylinders pumping air only (i.e., without fuel injection). In addition, the engine control method also provides the following features in combination with the above-described split air/lean mode: idle speed control, sensor diagnostics, air/fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, default operation, and exhaust gas and emission control device temperature control. In addition, the engine control method also changes to combusting in all cylinders under preselected operating conditions such as fuel vapor purging, manifold vacuum control, and purging of stored oxidants in an emission control device.

Abstract: A method is disclosed for controlling operation of an engine coupled to an exhaust treatment catalyst. Under predetermined conditions, the method operates an engine with a first group of cylinders combusting a lean air/fuel mixture and a second group of cylinders pumping air only (i.e., without fuel injection). In addition, the engine control method also provides the following features in combination with the above-described split air/lean mode: idle speed control, sensor diagnostics, air/fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, default operation, and exhaust gas and emission control device temperature control. In addition, the engine control method also changes to combusting in all cylinders under preselected operating conditions such as fuel vapor purging, manifold vacuum control, and purging of stored oxidants in an emission control device.

Abstract: An engine control system and method smoothes torque during transitions in a displacement on demand engine. A torque loss estimator generates a torque loss signal based on torque loss due to at least one of friction, pumping and accessories. A pedal torque estimator generates a pedal torque signal. An idle torque estimator generates an idle torque signal. A summing circuit generates a difference between the pedal torque signal and the idle torque and the torque loss signals and outputs a desired brake torque signal.

Abstract: A control method and system according to the present invention for a displacement on demand engine estimates cylinder air charge and/or predicts cylinder air charge for future cylinder interrupts. A model is provided that estimates cylinder air charge and/or predicts cylinder air charge for future cylinder interrupts. The model includes a history vector of inputs and states. The history vector inputs and states are updated when a cylinder firing interrupt occurs. An operating mode of the engine is determined. Based on the operating mode, model parameters and model inputs are selected. The cylinder air charge is estimated and predicted for future cylinder interrupts.

Abstract: An engine control system in a vehicle including a variable displacement internal combustion engine, an intake manifold coupled to the variable displacement internal combustion engine, a controller for controlling the displacement of the variable displacement internal combustion engine, and where the controller varies the spark for a reactivating cylinder during the transition from deactivation to reactivation.

Abstract: An engine control system and method smoothes torque during transitions in a displacement on demand engine. A torque loss estimator generates a torque loss signal based on torque loss due to at least one of friction, pumping and accessories. A pedal torque estimator generates a pedal torque signal. An idle torque estimator generates an idle torque signal. A summing circuit generates a difference between the pedal torque signal and the idle torque and the torque loss signals and outputs a desired brake torque signal.

Abstract: In an in-cylinder injection spark-ignition internal combustion engine including a plurality of cylinders and a catalyst device disposed in an exhaust system of the engine, a fuel is injected to at least one selected cylinder selected from the plurality of cylinders to be operated, and subsequently the fuel is injected to all cylinders to be operated. At this time, a warm-up controlled variable for the at least one selected cylinder is smaller than the warm-up controlled variable used when all cylinders are operated. In the in-cylinder injection spark-ignition internal combustion engine, the all cylinder operation is started and the warm-up control is started for all cylinders to warm up the catalyst device disposed in the exhaust system of the engine preferably when a fuel injection pressure exceeds a target value.

Abstract: An engine having a plurality of cylinder banks, each one of the banks having at least one cylinder. Each one of the banks is fed air through a corresponding one of a pair of manifold plenums. A main throttle body is provided having an outlet for feeding air to a pair of output ports, each one of such output ports being coupled to feed the air to a corresponding one of the pair of manifold plenums. The main throttle body has a main throttle plate disposed therein to control airflow passing to the outlet of the main throttle body. One of the pair of plenums has a plenum throttle plate for controlling air from the one of the pair of output ports of the main throttle body coupled thereto to cylinders in the bank of cylinders coupled thereto.

Abstract: An engine control system including a variable displacement internal combustion engine, a plurality of cylinders located in the internal combustion engine, a plurality of fuel injectors for providing fuel to the plurality of cylinders, a plurality of valves coupled to the plurality of cylinders, the plurality of valves controlling the air flow in and out of the cylinders, an actuation apparatus for actuating the plurality of valves, an intake manifold coupled to the internal combustion engine, a throttle coupled to the intake manifold, a controller electronically coupled to the fuel injectors, an accelerator pedal position sensor electronically coupled to the controller, and where the controller determines the number of the cylinders to provide with fuel and air and a desired engine output torque based on at least the accelerator pedal position sensor and the controller controls the throttle to control the amount of air entering the intake manifold, where the controller is capable of eliminating torque disturb

Abstract: A hybrid vehicle control apparatus is provided which can improve fuel consumption. There is provided: a cylinder cut-off determination section for determining whether all cylinders should be cut off; a cylinder cut-off cancellation determination section for determining whether cylinder cut-off cancellation conditions have been satisfied; a cylinder cut-off execution section for operating a spool valve when the cylinder cut-off determination section determines that cylinder cut-off is possible; and a cylinder cut-off control section for cutting off the cylinders of the engine based on the operating conditions of the cylinder cut-off determination section, the cylinder cut-off cancellation determination section and the cylinder cut-off execution section.

Abstract: The invention is directed to a method of starting an engine for internal combustion engines of a motor vehicle driven by gasoline direct injection with the engines being subdivided into several cylinder banks and a high pressure injection system being provided for each cylinder bank. During a first phase (A), an injection into the cylinders of a first cylinder bank in correspondence to their normal ignition sequence takes place and no injection is carried out in the cylinders of the remaining cylinder banks. In a subsequent second phase (B), injection takes place also into the cylinders of the other cylinder bank or banks.

Abstract: A method is disclosed for controlling operation of an engine coupled to an exhaust treatment catalyst. Under predetermined conditions, the method operates an engine with a first group of cylinders combusting a lean air/fuel mixture and a second group of cylinders pumping air only (i.e., without fuel injection). In addition, the engine control method also provides the following features in combination with the above-described split air/lean mode: idle speed control, sensor diagnostics, air/fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, default operation, and exhaust gas and emission control device temperature control. In addition, the engine control method also changes to combusting in all cylinders under preselected operating conditions such as fuel vapor purging, manifold vacuum control, and purging of stored oxidants in an emission control device.

Abstract: A system and a method to control torque during a mode transition in an internal combustion engine with a fully variable intake valve is disclosed. The mode transition may be a change in the number of active cylinders in a variable displacement engine, a change in compression ratio in a variable compression ratio engine, a gear change in a transmission coupled to the engine, a traction control event, and a rapid change in driver demand.

Abstract: A system for detecting conditions indicative of substandard performance of cylinders in a diesel engine includes an engine control unit disposed in operable communication with the engine and a computer disposed in informational communication with the engine control unit. The engine control unit is in operable communication with the engine through a communication element. The system measures the required fuel with all cylinders operating and enables a recommendation to be made with respect to corrective or maintenance measures that should be undertaken with respect to the cylinder. A method for utilizing the system includes comparing fuel requirements of the engine operating under power of all cylinders and under the successive arrest of each of the cylinders. The process is repeated until each cylinder is individually removed and all of the data can be compiled and considered to determine the performance of each individual cylinder.

Abstract: An engine catalytic converter misfire protection method and apparatus which controls engine parameters in response to the detection of potentially damaging cylinder misfire. A misfire counter responsive to engine cylinder misfires, counts misfires over a predetermined time period, with the positive changes in the counter output integrated and then compared with a threshold count to determine if the count corresponds to a damaging misfire condition. The apparatus and method simultaneously samples a short term fuel correction signal and compares the short term fuel correction signal with a second threshold. When both thresholds are exceeded substantially at the same time, the apparatus and method shut off fuel to the misfiring cylinder and shuts off the short and long term fuel control. Verification that the proper cylinder has the fuel shut off is made by repeating the control sequence to determine if the fuel has been shut off to the same cylinders.

Abstract: A fuel delivery control system controls fuel delivery for an engine having a plurality of cylinders and a electronically controlled fuel injection unit for controlling fuel delivered to each cylinder in response to control signals generated by an electronic control unit. The control unit, for each cylinder, determines an engine acceleration value derived from a crank position value generated by an engine crank position sensor, compares the acceleration value to a threshold value, and terminates fuel delivery to only the cylinders for which the comparison indicates unsatisfactory combustion, up to one half of the cylinders. The control unit operates to deliver a normal amount of fuel to cylinders for which the comparison indicates satisfactory combustion, and to cylinders for which fuel delivery has been terminated for a pre-set maximum number of times.

Abstract: A control device for a hybrid vehicle includes an actual intake gas negative pressure detection unit which detects an intake air negative pressure for the engine, an estimated intake gas negative pressure calculation unit which estimates an intake air negative pressure based on a revolution number of the engine and an opening degree of a throttle, and an engine control unit which compares an actual intake gas negative pressure obtained by the actual intake gas negative pressure detection unit with an estimated intake gas negative pressure obtained by the estimated intake gas negative pressure calculation unit. The engine control unit prohibits a fuel supply to the engine until the actual intake gas negative pressure matches the estimated intake gas negative pressure, and carries out the fuel supply to the engine when the actual intake gas negative pressure matches the estimated intake gas negative pressure.

Abstract: The invention is directed to a method of controlling catalytic converter heat losses during coasting shutoff in an internal combustion engine which includes a valve and a valve positioner having an adjustable stroke set point, and a catalytic converter. In the method, the stroke set point is fixed as a function of a temperature of the catalytic converter.

Abstract: A method of operating an internal combustion engine having a variable cam timing mechanism in cooperation with a plurality of deactivatable cylinders and corresponding intake valves includes the steps of scheduling a transition mode of the engine, determining a desired engine torque during the transition mode, determining a VCT phase angle based on the desired engine torque and operating the variable cam timing mechanism in accordance with the VCT phase angle to provide the desired engine torque during the transition mode.

Abstract: A control system for an internal combustion engine having a plurality of cylinders and a cylinder halting mechanism for halting operation of at least one of the plurality of cylinders. The cylinder halting mechanism is controlled to operate all of the plurality of cylinders or to halt the operation of the at least one of the plurality of cylinders. The operating state of the cylinder halting mechanism is detected based on the amount of change in the detected intake pressure of the engine.

Abstract: A diesel engine, having a plurality of individually controllable fuel injected cylinders, is operated in a skip firing mode to reduce smoke emissions during low power operation. The system senses certain identified engine operating parameters and when these parameters exceed predetermined thresholds for a predetermined time, then the skip firing is implemented. In another embodiment, it is possible to implement several different skip firing patterns dependent upon engine performance. Upon implementation of skip firing, the engine timing angle is reset by a fixed angle and a multiplication factor is included in the speed loop integrator to ensure that the appropriate fuel volume value is injected into each cylinder immediately upon initiation of skip firing. Skip firing is then disabled when another set of predetermined conditions is satisfied.

Abstract: An exhaust treatment system for an internal combustion engine includes a catalytic emission control device. When transitioning the engine between a lean operating condition and a stoichiometric operating condition, as when scheduling a purge of the downstream device to thereby release an amount of a selected exhaust gas constituent, such as NOx, that has been stored in the downstream device during the lean operating condition, the air-fuel ratio of the air-fuel mixture supplied to each cylinder is sequentially stepped from an air-fuel ratio of at least about 18 to the stoichiometric air-fuel ratio. The purge event is preferably commenced when all but one cylinders has been stepped to stoichiometric operation, with the air-fuel mixture supplied to the last cylinder being stepped immediately to an air-fuel ratio rich of a stoichiometric air-fuel ratio.

Abstract: An electronically controlled engine management system for a multi-cylinder engine unnoticeably disables and enables various cylinder groups to preserve fuel economy. The engine management system enables the operator to enjoy high torque represented from a multi-cylinder engine and to maintain good fuel economy.

Abstract: This invention is an automotive device or method used to disable fuel injector(s) on a sequential multi-port fuel injected engine in a modulated fashion. The modulation provides an equal average load to all cylinders. This technique improves fuel economy when properly compensated for the additional air proportion. Electronic control enables reserve power when needed by returning to normal operation. Also a device to reduce typical acceleration is presented.

Abstract: The invention provides a control apparatus of a cylinder injection of fuel type internal combustion engine executing a dilute combustion, which can satisfy a requirement of rapidly changing an engine torque while restricting a deterioration of a driving property and an exhaust gas as much as possible. In a control apparatus of a multicylinder engine executing a dilute combustion, in the case that a requirement of reducing and changing an engine torque of the internal combustion engine is applied, the control apparatus executes a fuel cut of a predetermined number of cylinders, and controls so that a torque of operating cylinders except the cylinders executing the fuel cut becomes the required engine torque.

Abstract: A fuel control system for an internal combustion engine includes a processor for determination of the timing and length of control pulse signals to an injector driver for turning an injector on and off. The method and an apparatus for delivering fuel to the injectors is according to a schedule that is adjusted throughout a variety of operating conditions with a minimum of chronometric or throughput loading by scheduling a circular queue of a plurality of buckets determined as a predetermined portion of a combustion cycle. Each bucket is defined by an interval initiated by an event triggered interrupt. At the interrupt, the processor dequeues a list of pointers to fueling information data storage for each cylinder previously assigned to the bucket. The method then assigns each cylinder to at least one selected bucket according to predetermined logic determination and an injector demand signal.

Abstract: A system is disclosed for implementing a technique for idling a diesel engine. The system comprises an engine controller, an air temperature sensor, and an engine speed sensor. The air temperature sensor provides a first signal indicative of an internal temperature of an intake manifold in fluid communication with the diesel engine. The engine speed sensor provides a second signal indicative of a rotational speed of a crankshaft of the diesel engine. In response to various other signals collectively indicating the diesel engine is idling, the engine controller controls the supply of fuel to the diesel engine as a function of the first signal. When the first signal is below a temperature level, engine controller supplies fuel to each combustion chamber of the diesel engine for a fixed period of time to achieve a desired range of rotational speeds of the crankshaft as indicated by the second signal.

Abstract: An engine control system including a variable displacement internal combustion engine, a plurality of cylinders located in the internal combustion engine, a plurality of fuel injectors for providing fuel to the plurality of cylinders, a plurality of valves coupled to the plurality of cylinders, the plurality of valves controlling the air flow in and out of the cylinders, an actuation apparatus for actuating the plurality of valves, an intake manifold coupled to the internal combustion engine, a throttle coupled to the intake manifold, a controller electronically coupled to the fuel injectors, an accelerator pedal position sensor electronically coupled to the controller, and where the controller determines the number of the cylinders to provide with fuel and air and a desired engine output torque based on at least the accelerator pedal position sensor and the controller controls the throttle to control the amount of air entering the intake manifold, where the controller is capable of eliminating torque disturb

Abstract: The invention is a strategy to detect spark plug misfires in a multiple spark plug per cylinder internal combustion engine (ICE). The present invention monitors spark plug misfires for each plug within each cylinder and initiates diagnostic fault code setting and failure mode actions such as modifying spark timing and the air/fuel ratio for the cylinder with the misfiring plug to optimize emissions and performance. The strategy modifies spark timing (such as spark retard) of a spark plug not under test but within the same cylinder of the tested spark plug and tests the tested spark plug for misfire (such as changes in crankshaft velocity or acceleration). The amount of spark retard invoked can be a calibrated value such as 30 or 50 degrees off Maximum Brake Torque (MBT) timing. The invention provides improvement over the prior art in that the strategy does not require the complete disabling of a spark plug within the same cylinder as the tested spark plug.

Abstract: An engine catalytic converter misfire protection method and apparatus which controls engine parameters in response to the detection of potentially damaging cylinder misfire. A misfire counter responsive to engine cylinder misfires, counts misfires over a predetermined time period, with the positive changes in the counter output integrated and then compared with a threshold count to determine if the count corresponds to a damaging misfire condition. The apparatus and method simultaneously samples a short term fuel correction signal and compares the short term fuel correction signal with a second threshold. When both thresholds are exceeded substantially at the same time, the apparatus and method shut off fuel to the misfiring cylinder and shuts off the short and long term fuel control. Verification that the proper cylinder has the fuel shut off is made by repeating the control sequence to determine if the fuel has been shut off to the same cylinders.

Abstract: In order to avoid an undesired and damaging ignition in the case of the failure of a valve in an internal combustion engine with electromechanical valve drive, a control device interrupts the injection and/or the ignition for at least the cylinder in question when such a failure of a valve is detected by the control device.

Abstract: An engine can be operated in different modes by varying the number of operating cylinders. In a reduced operating cylinder mode, the intake valve of the inoperative cylinder is maintained closed throughout all four strokes of a four-stroke cylinder cycle. The exhaust valve of the same inoperative cylinder is opened only in the suction stroke and the exhaust stroke. The inoperative cylinder sucks high pressure exhaust gas through the opened exhaust valve in the suction stroke and discharges it through the opened exhaust valve in the exhaust stroke after the compression stroke and the combustion stroke. The intake/exhaust valve control for the inoperative cylinder is started from the suction stroke after one combustion cycle of the inoperative cylinder when the engine is switched from an all cylinder-operating mode to a reduced cylinder-operating mode.

Abstract: A controller for a cylinder cut-off type internal combustion engine is provided for ensuring an activated state of catalysts in cylinders, which are stopped during a partial cylinder operation, at all times to maintain favorable emission characteristics upon switching from the partial cylinder operation to a full cylinder operation, and for maintaining a satisfactory fuel consumption rate by conducting the partial cylinder operation to the utmost. The cylinder cut-off type internal combustion engine can be switched between the partial cylinder operation and the full cylinder operation. Exhaust gas from cylinders in a right bank, which are switched off during the partial cylinder operation, and from cylinders in a left bank is purified by two catalyst units in exhaust pipes independent of each other.