Abstract: There is provided a fuel supply control system for an internal combustion engine, which is capable of controlling fuel cutoff according to an amount of oxygen stored in a catalytic converter to thereby enhance the purification rate of the catalytic converter while maintaining excellent fuel economy, thereby making it possible to improve exhaust emission characteristics. An amount of oxygen stored in the catalytic converter 13 arranged in an exhaust pipe 12 of an engine 3 is estimated (steps S1 to S29). A deceleration condition of the engine is detected (steps S35, S36). When the deceleration condition is detected, supply of fuel to the engine is cut off (step S41). The cutoff of fuel supply is controlled based on the oxygen storage amount OSC (steps S31, S32, S40, S41).

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: 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 control method and apparatus for regulating the power output of an engine in a marine propulsion system provides the storage of several sets of numerical values in which each numerical value in each set is associated with a particular cylinder of the engine. In addition, each numerical value in each set represents the number of consecutive firing events experienced by each cylinder prior to the occurrence of a skip fire event. A numerical value of zero indicates continuous skip fire events for a particular cylinder and a numerical value equivalent to some predetermined maximum numerical value, such as 255, represents a continuous firing regime for the associated cylinder.

Abstract: A method for controlling mode transitions, such as from stratified to homogeneous mode, in a direct injection engine adjusts a number of cylinders carrying out combustion to prevent engine torque disturbances. Cylinder activation is used when changes in cylinder air/fuel ratio cannot be compensated using ignition timing adjustments. In addition, the number of cylinders to activate is also determined and measures are taken if the number of cylinders determined are not available to be activated.

Abstract: A start assist device for an engine having a means for supplying fuel to fewer than all of the cylinders of the engine at engine cranking speeds that are less than the speed wherein the fuel injection system provides fuel to all of the cylinders. In one embodiment for a diesel locomotive engine, fuel is supplied to two cylinders beginning at 45 RPM to assist the engine starter in achieving an engine cranking speed of 90 RPM wherein the fuel injection system begins to provide fuel to all of the cylinders.

Abstract: A method for controlling mode transitions, such as from stratified to homogeneous mode, in a direct injection engine adjusts a number of cylinders carrying out combustion to prevent engine torque disturbances. Cylinder activation is used when changes in cylinder air/fuel ratio cannot be compensated using ignition timing adjustments. In addition, the number of cylinders to activate is also determined and measures are taken if the number of cylinders determined are not available to be activated.

Abstract: A method of operating an externally-ignited internal-combustion engine which includes a plurality of engine cylinders each provided with cylinder valves, an ignition device, a fuel injection device and an electromagnetic valve drive for operating the cylinder valves, and which further includes an electronic engine control for controlling the cylinder valves, includes the following steps: monitoring the operation of the ignition device and/or the fuel injection device of each cylinder; and, during cold start and/or when a spark failure and/or an ignition failure is detected in one of the cylinders during the monitoring step, adapting the control of the electromagnetic valve drives of that cylinder to the changed operational conditions.

Abstract: A startup control apparatus of an internal combustion engine is provided wherein when an engine starting capability determining device determines that the engine can be successfully started even if driving of part of the fuel injector valves is stopped during engine startup, the fuel injection is stopped with respect to the part of the fuel injector valves. With this arrangement, overshoot of the engine speed that would otherwise occur upon the start of the engine can be suppressed, and unburned fuel components can be prevented from being discharged, thus assuring improved exhaust gas characteristics and improved fuel efficiency.

Abstract: An engine control system for an engine system with electromagnetically operated intake and exhaust valves has a control unit. The control unit is arranged to decide whether each of the intake and exhaust valves is put in an abnormal condition, to close a normal valve of the intake and exhaust valves when one of the intake and exhaust valves is put in the abnormal condition, and to stop the current-flowing to a primary ignition coil when one of the intake and exhaust valves is put in the abnormal condition and when the primary ignition coil is not starting the current-flowing.

Abstract: A method and an arrangement for reducing vibrations in an internal combustion engine (2) which has a plurality of drive units (3-8) connected to a common output shaft (9). These are equipped with a combustion chamber and inlets (34-39) for fuel from organs for fuel supply. Any one of the driving units (7) can be switched from a normal operating condition to an alternative operating condition, in which the supply of fuel to the drive unit is blocked, which causes an alteration in the torque of the driving unit which has been thus switched. The amount of fuel supplied to the drive units which are in a normal operating condition is distributed according to a chosen pattern in order to create torques in these which cause a chosen suppresion of vibrations.

Abstract: A method for controlling mode transitions, such as from stratified to homogeneous mode, in a direct injection engine adjusts a number of cylinders carrying out combustion to prevent engine torque disturbances. Cylinder activation is used when changes in cylinder air/fuel ratio cannot be compensated using ignition timing adjustments. In addition, the number of cylinders to activate is also determined and measures are taken if the number of cylinders determined are not available to be activated.

Abstract: A method for controlling mode transitions, such as from stratified to homnogeneous mode, in a direct injection engine adjusts a number of cylinders carrying out combustion to prevent engine torque disturbances. Cylinder activation or deactivation is used when changes in cylinder air/fuel ratio cannot be compensated using ignition timing adjustments. In addition, the number of cylinders to activate or deactivate is also determined.

Abstract: There is provided an engine control apparatus with electromagnetically driven intake and exhaust valves which can widen the dynamic range of engine brake torque. The valve open timing of the electromagnetic exhaust valve during fuel cut is made to be variable between the initial stage of expansion stroke and the late stage thereof so as to control the magnitude of engine brake torque.

Abstract: The present invention is an ignition control system for an engine having at least one combustion chamber and an ignition element for initiating combustion in the chamber. As one aspect of the ignition control, a switching circuit is provided for controlling the firing of the ignition element based upon either a signal received from a mechanism which detects and outputs a first firing timing signal or a computing mechanism which outputs a second firing timing signal based upon the first firing timing signal. As a second aspect of the ignition control, ignition elements are paired and fired together. In this arrangement, the ignition control includes a mechanism for counting outputted firing signals and assigning them values. These values are used to control the firing of the pairs of ignition elements, permitting the pairs of elements to be fired such that combustion initiation in individual combustion chambers corresponding is controllable.

Abstract: Disclosed is a control system and method of a two cycle direct fuel injection engine capable of smoothly suspending combustions in the cylinder during light load operation of the engine. Based on a map parameterizing the engine speed and the target engine load, it is judged whether or not, when the engine load is in the light load condition, the target engine load is located in a suspending area in which misfires tend to occur. If the target engine load is not in the suspending area, since there is no possibility of misfire, the normal combustion cycle continues to operate. On the other hand, if the target engine load enters into the suspending area, the control system instructs the fuel injection and ignition apparatuses so as to suspend fuel injection and spark ignition with a frequency determined according to the magnitude of the engine load. The frequency is determined by a predetermined formula such that it is reduced as the engine load becomes high and is increased as the engine load becomes low.

Abstract: A fuel injection control strategy and system for engines for maintaining good performance under normal running conditions and also for providing cylinder engine speed slow-down under abnormal conditions by cylinder skipping. Transitional operation between these modes is improved by changing injection timing and/or injection duration of the operating cylinders during this time. Adjustment in spark timing may also be incorporated along with this routine.

Abstract: An automobile includes an engine and an engine controller. The engine includes multiple cylinders. Each cylinder hyas a fuel injector connected to the engine controller. The engine controller has a first output which activates a first fraction of the fuel injectors. In addition, the engine controller has a second output which activates a second fraction of the fuel injectors. The engine controller also has an input which provides a timing signal synchronous with rotation of the engine and a sequencing circuit responsive to the timing signal. The sequencing circuit periodically alternates between the first and second output in synchronization with the rotation of the engine.

Abstract: A combustion state detecting apparatus for an internal-combustion engine improves the signal-to-noise ratio of an ionic pulse signal to achieve good interfacing characteristic, high detection accuracy, and high control reliability without adding to cost. An electronic control unit (2A) which detects the combustion state in a spark plug according to an ionic pulse signal (Gi) includes: an edge detecting circuit (36) for detecting an end edge of an ionic pulse contained in the ionic pulse signal in a detection zone from a second reference crank angle to a first reference crank angle; a level detecting circuit (37) for detecting the level of the ionic pulse signal at the first reference crank angle; and a circuit (38) for determining the combustion state of the internal-combustion engine according to a detection result (Ni) received from the edge detecting circuit and a detection result (Li) received from the level detecting circuit.

Abstract: A method is provided for monitoring catalyst efficiency in a catalytic converter of a motor vehicle, comprising the steps of: (a) detecting an oxygen level of an exhaust gas from the vehicle's engine by using an oxygen sensor positioned at the outlet of the catalytic converter; (b) terminating fuel flow to the vehicle's engine; (c) detecting a change in the oxygen level in response to terminating fuel flow; (d) determining a time period from termination of fuel flow to detection of the change in oxygen level; and then (e) compensating this time period with respect to an exhaust flowrate, such that the compensated time period is indicative of catalyst efficiency of the catalytic converter. More specifically, the exhaust flowrate is determined from a manifold absolute pressure and an engine rotational speed of the engine. To achieve reliable and consistent results, catalyst monitoring of the present invention is only enabled under preferred vehicle operating conditions.

Abstract: A multi-cylinder spark ignition internal combustion engine is described having two banks of cylinders 10a, 10b. One bank of cylinders may be selectively disabled by cutting off its fuel supply while continuing to receive air. The exhaust system includes an NO.sub.x trap 20 to store NO.sub.x gases while the exhaust gases contain excess air. During part load operation, the engine is run with one bank of cylinders disabled most of the time during which NO.sub.x gases are stored in the NO.sub.x trap 20. In order to permit the trap 20 to be regenerated or purged periodically, both bank are fired at is the same time for short intervals to supply a stoichiometric or reducing mixture to the exhaust system.

Abstract: A method and apparatus for cranking of an internal combustion engine in an AC electric traction motor propelled vehicle using inverters normally coupled to supply power to each of a plurality of AC motors. The inverters have DC input terminals connected between a relatively positive DC bus and a relatively negative DC bus and the DC buses are connected to DC output terminals of a rectifier. The rectifier has AC input terminals connected to stator terminals of a synchronous generator. The generator includes a field winding and a rotor connected in driving relationship to a crank shaft of the engine.

Abstract: An engine control for an engine powering a watercraft is disclosed. The engine has a body defining at least two combustion chambers. An air supply system supplies air to the combustion chambers, the air supply system including a throttle control for controlling the flow rate of air to the engine, the throttle control moveable between an open and a closed position. A fuel supply system supplies fuel to the combustion chambers. At least one ignition element ignites the air and fuel supplied to the combustion chambers. At least one exhaust passage leads from the combustion chamber to a point exterior to the body through which exhaust may pass. Exhaust control means are provided for controlling the timing of the flow of exhaust through the passage.

Abstract: A throttle control apparatus that maintains a vehicle's ability to run during a throttle system failure includes a throttle-controlling ECU that calculates a throttle opening instruction value from an accelerator stroke signal outputted from an accelerator pedal sensor, and supplies a motor with a current value based on the instruction value, to control the opening of a throttle valve. If the deviation between the instruction value and the output value from a throttle sensor is greater than a reference value, the ECU determines that there is a system failure. If it is determined that a system failure exists, an internal combustion engine controlling ECU varies the number of cylinders of the engine in operation to vary the engine output, depending on whether the amount of depression of the accelerator pedal by the driver is greater than a predetermined value.

Abstract: The invention is a method for a cylinder cutout system in a compression ignition engine utilizing a plurality of electronic unit injectors. An electronic controller, in communication with the compression ignition engine, is configured to receive a plurality of sensor signals indicative of current engine operating parameters. In response to the received signals, the electronic controller produces an injector signal. Included in each of the electronic unit injectors is a solenoid, that when activated in response to the injector signal received from the electronic controller, will facilitate injection of fuel to a corresponding cylinder. A predetermined plurality of the electronic unit injectors will be deactivated in response to the injector signal.

Abstract: Disclosed is a control system and method of a two cycle direct fuel injection engine capable of smoothly suspending combustions in the cylinder during light load operation of the engine. Based on a map parameterizing the engine speed and the target engine load, it is judged whether or not, when the engine load is in the light load condition, the target engine load is located in a suspending area in which misfires tend to occur. If the target engine load is not in the suspending area, since there is no possibility of misfire, the normal combustion cycle continues to operate. On the other hand, if the target engine load enters into the suspending area, the control system instructs the fuel injection and ignition apparatuses so as to suspend fuel injection and spark ignition with a frequency determined according to the magnitude of the engine load. The frequency is determined by a predetermined formula such that it is reduced as the engine load becomes high and is increased as the engine load becomes low.

Abstract: A method and apparatus for improving efficiency and reducing emissions of a vehicle's multi-cylinder internal combustion engine. The engine runs at best BSFC by intermittently disabling cylinders for torque control. The engine runs as an air compressor for braking, and after braking, runs as an air motor driven by the stored compressed air. The air motor capability permits stopping all fuel flow when the accelerator is released at any engine speed. Variable engine valve control eliminates the conventional throttle and EGR valve, and is utilized for maximum thermodynamic efficiency during air operation. A camshaft retard is utilized to minimize the pressurized components and to prevent cooling the catalyst during air motor operation.

Abstract: An apparatus for determining if a combustion condition in a combustion chamber of an internal combustion engine occurred includes a combustion sensor for sensing the occurrence of the combustion condition in the combustion chamber and producing a combustion signal responsive to the combustion condition, a temperature sensor for sensing a temperature condition in an exhaust passage from the combustion chamber and producing a temperature signal having a characteristic indicative of the sensed temperature condition, and a controller connected for receiving the combustion signal and the temperature signal and operable in the absence of receipt of an expected combustion signal to determine if the combustion condition occurred by comparing the temperature signal characteristic with a predetermined characteristic value indicative of the occurrence of the combustion condition in the combustion chamber.

Abstract: A combustion state detector apparatus for an internal combustion engine has a current detection device for detecting a current flowing between the ignition plug and a ground, and an ignition driving device for driving the ignition plug on the basis of an ignition instruction signal from an electronic control device of the internal combustion engine. An independent unit including a current detection device and an ignition driving device, is provided for each cylinder of the internal combustion engine. With respect to each cylinder, the apparatus determines whether a misfire has occurred on the basis of the current flowing between the ignition plug and the ground at the time of combustion. The apparatus is also capable of detecting abnormalities and/or wire breakages in a signal system provided for signal transmission between each independent unit and the electronic control device of the internal combustion engine.

Abstract: In order to damp shocks due to load alterations to as great an extent as possible, indexed base torque of the engine is determined which corresponds to a coupling torque able to be tapped off at the engine crankshaft and not reduced by engine loss torques. The indexed base torque is then converted by filtering into an indexed setpoint torque which exhibits a smaller rise compared to the indexed base torque in response to a load alteration. Finally, a setpoint ignition angle is derived from the an indexed setpoint torque.

Abstract: A cylinder-by-cylinder air-fuel ratio-estimating system for an internal combustion engine includes an air-fuel ratio sensor arranged in the exhaust system of the engine. The air-fuel ratio of a mixture supplied to each of the cylinders of the engine is estimated based on an output from the air-fuel ratio sensor, by using an observer for observing the internal operative state of the exhaust system based on a model representative of the behavior of the exhaust system. The estimated air-fuel ratio of the mixture supplied to each of the cylinders is initialized to a value corresponding to the output from the air-fuel ratio sensor, depending upon operating conditions of the engine.

Abstract: A method for detecting irregular combustion processes in a multicylinder diesel internal combustion engine includes detecting incorrect injections and non-injections by recording combustion noise in individual cylinders through the use of one or more structure-borne noise sensors. Subsequently, a check is performed as to whether or not sensor signals exceed threshold values individual to each cylinder within or outside fixed measurement windows.

Abstract: A control device for a two-cycle internal combustion engine combustion engine of the fuel injection type, which is provided with an ignition control device and a fuel control device, wherein the fuel control device includes an injection mode-controlling means for controlling a timing of fuel injection by selecting a particular fuel injection mode, i.e. selecting the mode from a one-injection per revolution mode where the injection of fuel is performed on every revolution of a crank shaft of the internal combustion engine and a thinned-out injection mode where the injection of fuel is performed on plural revolutions of the crank shaft. The fuel control device is provided also with an injection quantity-controlling means for controlling the quantity of fuel to be injected.

Abstract: A process is disclosed for controlling a multiple cylinder internal combustion engine in which exhaust gases undergo subsequent treatment. To ensure a gaseous exchange, air is supplied to the individual cylinders through inlet devices and exhaust gases are discharged through outlet or exhaust devices. The inlet and outlet devices are independently driven but their opening and closing times may be synchronized. Beginning in the cold start phase until the warming up phase, fuel is supplied to only part of the cylinders that act as an engine and the supply of fuel to the other cylinders is cut off. The other cylinders work then as compressors. The air volume heated in these cylinders by compression flows through the outlet device into the exhaust gas system and reacts with the exhaust gases.

Abstract: With a protection system for a turbocharged internal combustion engine, it is determined, using a parameter characterizing the turbocharging, whether an overshoot or a serious defect, such as for example a hose failure, is present in the turbocharging pressure system and, according to the case, a 1st or 2nd suppression pattern for suppressing fuel injection to individual cylinders is activated. In the event of repeat occurrences, the protection system according to the invention responds considerably faster than in the first occurrence of the defect. An error correction is possible under certain operating conditions, and the original response time is restored.

Abstract: A method for engine start-up reducing white smoke and the start-to-idle time. The method includes the combination of producing two sub-fuel injections into the cylinders of the internal combustion engine at different points in the position of at least one injection valve of the engine and reducing the number of combusting cylinders in half. The two sub-fuel injections reduce the start-to-idle time. Once the engine is idling, the half cylinder operation reduces the white smoke emitted therefrom. The two sub-fuel injections are also employed when in half cylinder operation to reduce noise.

Abstract: In a V type engine comprising a catalyst in each of banks, when a fuel cut requirement on the basis of a traction control is generated, cylinders in which the fuel is cut are controlled to be switched between right and left banks. For example, when a requirement for a fuel cut with respect to two cylinders, at first, after the fuel cut of two cylinders are performed in the right bank for a predetermined time, the fuel cut of two cylinder are performed in the left bank for a predetermined time and this operation is repeated during a continuing time of the fuel cut. Accordingly, a thermal damage due to the fuel cut can be prevented from concentrating only to one catalyst.

Abstract: An apparatus and method for reducing white smoke during start up of a compression ignition engine is disclosed. The apparatus includes an engine cylinder, a fuel injector, an engine speed sensor, and a microprocessor. The microprocessor preferably includes an engine speed controller that governs the engine speed to a desired value. The microprocessor issues a first fueling level corresponding to a difference between an actual engine speed and the desired engine speed signal. The microprocessor quits fueling the engine cylinder then determines a second fueling level. A determination about whether the cylinder is firing is then based on a comparison between the first and the second fueling level.

Abstract: An combustion state detecting apparatus for an internal-combustion engine is equipped with: an ignition coil (4) for applying a high voltage (V2) for igniting to the spark plugs (8a through 8d) of the cylinders of an internal-combustion engine; an ionic current detecting circuit for applying a bias voltage (VBi) to at least one spark plug to detect ionic currents (ia, ib) flowing via the spark plug which has just been subjected to ignition control; comparator circuits (14a, 14b) which compare detected ionic current signals (Eia, Eib) with threshold values (TH1, TH2) and turn them into ionic current pulses (Gia, Gib); and an ECU (2A) which drives the ignition coil according to a crank angle signal (SGT) and determines the combustion state of the internal-combustion engine. The ECU changes the threshold values for each ignition control and judges the combustion state according to the respective threshold values and the state in which the ionic current pulses are generated.

Abstract: A method for determining an additional injected quantity upon reactivation of an internal combustion engine by multiplying a load-dependent wall-film quantity by a correction factor. The correction factor is modulated up during the coasting deactivation time until reactivation with a first time constant. The correction factor is modulated back down during reactivation with a second time constant.

Abstract: A number of embodiments of feedback control systems for two-cycle, internal combustion engine management systems. Each embodiment employs an exhaust system sensor which senses the exhaust gases by drawing exhaust gases from the exhaust of the engine. In some instances this is done directly from the cylinder and in others it is done in the exhaust system. In each embodiment, the sensor is provided in an accumulator chamber so as to provide an accurate signal of instantaneous engine running conditions. The use of the accumulator chamber insures that the combustible gases will not be diluted with fresh air charge, but will be able to purge from cycle to cycle so as to provide cycle-by-cycle information. Various arrangements are provided for protecting the sensor element including serpentine flow paths, shields, the direction in which the exhaust gases are delivered, lubricant catalysts, conduit shape, sensor cooling and combinations of these features.

Abstract: A high horsepower diesel engine is operated in a skip firing mode in which the engine includes a plurality of individually controllable, fuel injected cylinders. The system senses that the engine is operating in a low horsepower mode and has a low fuel demand and thereafter selects a firing pattern of cylinders to be fired during each revolution of the engine crankshaft based upon the values of the sensed fuel demand and engine horsepower. The pattern selected for firing the cylinders is arranged such that all cylinders of the engine are fired within a preselected number of crankshaft rotations. The system also senses the engine air-fuel ratio and adjusts the pattern of cylinders being fired so as to maintain exhaust emissions below a preselected level. Additionally, the pattern of fired cylinders may be adjusted to maintain engine operating temperature and as a function of engine speed.

Abstract: In a process and in a device for monitoring a fuel delivery system, in particular a common rail system for a diesel engine, a defect in the delivery system is found when a signal from a temperature sensor and/or a pressure sensor deviates from a predetermined value.

Abstract: The invention provides a method for shutting down and restarting individual cylinders of a multicylinder internal combustion engine by deactivating the charge change valves and the fuel injection. According to the invention, in shutting down a selected cylinder, the exhaust valve is disconnected first in all cases. Thereafter, the intake valve and fuel injection for the selected cylinder are controlled such that the last fuel injection into that cylinder takes place immediately before the last intake cycle. When a cylinder is restarted, the exhaust valve is always operated first, and only thereafter is the intake valve opened, with the first fuel injection always taking place immediately before the first intake cycle.

Abstract: A cylinder-disabling control system for a multi-cylinder engine provided with an exhaust manifold to which each exhaust port is connected, which control system comprises an engine performance sensor, an operation mode selector for selecting the cylinder-disabling mode or the all-cylinders-engaged mode, depending on the engine performance, and a resuming controller for resuming the disabled cylinders one at a time when switching from the cylinder-disabling mode to the all-cylinders-engaged mode, thereby allowing for continuous and smooth switching between the cylinder-disabling mode and the all-cylinders-engaged mode.

Abstract: A method for cylinder cutout in an internal combustion engine, with the engine having charge exchange valves on a portion of its cylinders. The charge exchange valves can be cut out as well as a switchable fuel supply, both of which can be switched from a cut-out or cut-off state to a cut-in state and vice versa. In order to provide a method for cylinder cutout that permits a safe transition from operation in which they are not cut out to one in which they are cut out, and by which the effects of cylinder cutout on fuel consumption and exhaust behavior are minimized, the fuel supply and the charge exchange valves may be cut out separately or in parallel. Before cylinder cutout, both the time required to cut out the charge exchange valves and the time required to cut off the fuel supply are calculated. Then these two times are compared and a waiting time is determined for the shorter process. When the next reference mark on the internal combustion engine is reached, both processes can proceed independently.

Abstract: An automobile includes an engine and an engine controller. The engine includes multiple cylinders. Each cylinder has a fuel injector connected to the engine controller. The engine controller has a first output which activates a first fraction of the fuel injectors. In addition, the engine controller has a second output which activates a second fraction of the fuel injectors. The engine controller also has an input which provides a timing signal synchronous with rotation of the engine and a sequencing circuit responsive to the timing signal. The sequencing circuit periodically alternates between the first and second output in synchronization with the rotation of the engine.

Abstract: Two stroke internal combustion engine control compensates for diagnosed cylinder misfire conditions characterized by improper combustion, during a cylinder combustion event, of an air/fuel mixture in an engine cylinder by learning a required number of cylinder combustion events to periodically be skipped to allow for removal of residual combustion elements from the cylinder following improper combustion therein, and by periodically postponing cylinder combustion over the learned number of events. The learned number of events may vary across engine cylinders, across engine operating conditions, and further may vary as a function of each cylinder's misfire propensity and severity over various engine operating conditions.

Abstract: A fuel induction system for an internal combustion engine which includes a throttle valve that is positioned substantially open under idle and near idle engine running conditions. The system includes means for disabling one or many of the cylinders in order to maintain a low engine rotational speed at idle and near idle and also means for selectively disabling the cylinders in such a manner as to provide the smoothest running engine possible in those instances where one or many of the engine's cylinders are disabled. Smooth transitional control is achieved by varying ignition and/or fuel control.

Abstract: A fuel injection control system for controlling fuel delivery a necessary amount of fuel according driving conditions through at least leading and trailing fuel injections for each of cylinders every cycle in a specified range of driving conditions and executes fuel cut-off control according to a fuel cut-off pattern upon an occurrence of a demand for an engine torque drop starts said fuel cut-off control from when injection timing for leading fuel injection of a cylinder is reached first after the occurrence of the torque drop command.