Abstract: The driving force ECU calculates a restricted driving force for a driving force restricting control, by using a Proportional-Integral-Differential control formula which utilizes a difference between a target acceleration varied depending on a vehicle speed and an actual acceleration of the vehicle. The driving force ECU adjusts (changes) a proportion gain K1 of the Proportional-Integral-Differential control formula based on an inclination angle ? of a road in such a manner that a value of the proportion gain K1 used when the inclination inclination angle ? is relatively large is smaller than a value of the proportion gain K1 used when the inclination inclination angle ? is relatively small. The driving force ECU performs a driving force restricting control by selecting, as a target driving force used for the driving force restricting control, a pedal required driving force or the restricted driving force, whichever is smaller.

Abstract: The present invention relates to a method for controlling an actuator (4) comprising a mobile element (60), the method comprising steps of receiving a set-point signal and two position-measurement signals (A, B) of the mobile element (60) acquired by different position sensors (7), calculating a deviation between the two position-measurement signals (A, B), generating (102) a control signal (S) for controlling a movement of the mobile element (60) on the basis of the set-point signal (E) and at least one of the position-measurement signals (A, B), the method being characterised in that when the deviation between the position-measurement signals (A, B) crosses (201) a predetermined threshold, said method comprises the following steps: setting (202) the control signal (S) to a constant value so as to immobilise the mobile element (60), for each of the two measurement signals (A, B), calculating an interval of positions associated with the measurement signal (A), and detecting an output of the value of a measure

Abstract: An electric charging control device is obtained which detects welding abnormality of an electric contactor(s) along charging passages from an electric charging plug reaching a main battery; electric charging contactors and main electric contactors are connected in series; a first voltage monitoring circuit connected between power-supply points P1 and N1, a second voltage monitoring circuit connected therebetween, and a voltage-level detection circuit connected between the midpoints P2 and N2 are provided for producing a first voltage detection signal DET1, a second voltage detection signal DET2, and a main voltage detection signal DET0, each of which is a respective determination logic signal responding to the presence or absence of a monitored voltage; and a test voltage is received from either one of the main battery and a ground-based electric charging power-source apparatus, so that the presence or absence of welding abnormality in any one of the contactors is determined.

Abstract: An exhaust gas purification system for vehicle provided on an exhaust pipe connected to an exhaust side of an engine for purifying an exhaust gas of the engine includes a housing mounted on the exhaust pipe, a front end catalyst incorporated in the housing to primarily purify the exhaust gas flowing into the housing through the front end portion of the housing, a rear end catalyst incorporated in the housing to secondarily purify the exhaust gas passing through the front end catalyst before the exhaust gas flows out to the rear end portion of the housing, and a controller connected to the exhaust pipe at a front end portion of the housing to control the concentration of unburned fuel contained in the exhaust gas according to temperature of exhaust gas flowing into the housing and speed of the vehicle.

Abstract: In a control system for an internal combustion engine, the internal combustion engine includes a first exhaust catalyst that is a three-way catalyst disposed in an exhaust path of the internal combustion engine, a second exhaust catalyst that is a three-way catalyst disposed in the exhaust path on a downstream side of the first exhaust catalyst, and a motor configured to drive the internal combustion engine. The control system includes an electronic control unit configured to, when operation of the internal combustion engine is stopped, stop fuel injection in the internal combustion engine and then, execute motoring in which the internal combustion engine is rotationally driven using drive power of the motor, and execute the motoring in a range in which an oxygen occlusion amount of the first exhaust catalyst becomes an oxygen occlusion amount smaller than an upper limit oxygen occlusion amount of the first exhaust catalyst.

Abstract: A method for the quality assurance of exhaust gas behavior in a motor vehicle, particularly in a hybrid vehicle, includes monitoring an on-board-diagnosis function; providing a journey counter a diagnosis counter, and a nominal diagnosis frequency value; incrementing the journey counter following the beginning of a driving cycle; generating an actual diagnosis frequency value using a combination of the diagnosis counter and the drive counter; and establishing a difference between the nominal diagnosis frequency value and the actual diagnosis frequency value. If the difference falls short of a threshold: a control method is selected, which is designed to successfully complete a currently running OBD of the OBD function and to initiate and complete a non-running OBD. Following the completion of the OBD of the OBD function, the diagnosis counter is incremented and the motor control restored to an original motor control.

Abstract: Apparatus and methods of determining altitude information with a radar receiver with quadrature detection is provided. A method includes generating baseband frames. An oscillator signal is created within each of the baseband frames. A return of the oscillator signal is coupled to a first input of a mixer. Moreover, the oscillator signal is coupled to a second input of the mixer. A phase of the oscillator signal is selectively changed between two or more distinct values. Timing of the change being based at least in part on a baseband frame timing of the generated baseband frames. Samples of an output of the mixer are selectively collected further based at least in part on the baseband frame timing. The collected samples are processed to compute altitude information.

Abstract: To meet stringent emission standards and improve performance of two-stroke crankcase-scavenged engines, the muffler (13) of the engine is provided with mixing means (130, 31) for mixing the exhaust gases (42) resulting from the mixture participating in combustion and gases resulting from scavenging, so that a substantially homogenous gaseous mixture is formed within the muffler (13), and means (81) for sensing oxygen concentration is located in the homogeneous gaseous mixture and are configured to provide an output value to a control unit (80) for controlling supply of fuel to the engine and thereby the air-fuel ratio in the combustion chamber (41). The muffler (13) suitably is provided with a catalytic element (140), preferably a three-way catalyst. The engine (1) preferably is a stratified charge engine.

Abstract: An internal combustion engine mounted on a vehicle includes an exhaust passage provided with a catalyst. A controller for the internal combustion engine includes a processor. The processor is configured to perform an auto-stopping process on the engine when the engine is idling, perform an auto-restarting process on the engine when the engine is automatically stopped, correct an amount of fuel injected into the engine so that the fuel injection amount of the engine is increased by a correction amount after the auto-restarting process is started, and change the correction amount in accordance with an amount of oxygen stored in the catalyst at a point of time when the auto-stopping process is started.

Abstract: To meet stringent emission standards and improve performance of two-stroke crankcase-scavenged engines, the muffler (13) of the engine is provided with mixing means (130, 31) for mixing the exhaust gases (42) resulting from the mixture participating in combustion and gases resulting from scavenging, so that a substantially homogenous gaseous mixture is formed within the muffler (13), and means (81) for sensing oxygen concentration is located in the homogeneous gaseous mixture and are configured to provide an output value to a control unit (80) for controlling supply of fuel to the engine and thereby the air-fuel ratio in the combustion chamber (41). The muffler (13) suitably is provided with a catalytic element (140), preferably a three-way catalyst. The engine (1) preferably is a stratified charge engine.

Abstract: A device may include a driver integrated circuit (IC) comprising a first control unit and a second control unit, a first solenoid that is electrically coupled to the first control unit, a second solenoid that is electrically coupled to the second control unit; at least one sensor, a clock that synchronizes a microcontroller and the driver IC, and a peripheral bus that communicatively couples the first control unit, the second control unit. The microcontroller and the driver IC form an outer control loop that actuates the first solenoid and the second solenoid, and the first control unit, the second control unit, and the at least one sensor form an inner control loop that controls the first solenoid and the second solenoid.

Abstract: An air-fuel ratio control system of an internal combustion engine comprises a fuel amount determiner for determining a fuel command value. The fuel amount determiner has a feedback control mode in which the fuel amount determiner determines a running state reference coefficient corresponding to a running state detected by a running state detector based on a first correspondence stored in the memory, determines a running state compensation coefficient corresponding to the running state detected by the running state detector based on a second correspondence stored in the memory, determines a feedback compensation coefficient used to cause an air-fuel ratio to reach a value closer to a theoretical air-fuel ratio based on an output of the air-fuel ratio sensor, and determines the fuel command value using a formula including the determined running state reference coefficient, the determined running state compensation coefficient, and the determined feedback compensation coefficient.

Abstract: A sensor control apparatus includes: a gas sensor including an oxygen concentration detection cell having a first solid electrolyte body, a reference electrode and a detection electrode, and a heater; an electric current supply unit that supplies electric current to the oxygen concentration detecting cell; an activation determination unit; a heater control unit that sets a first target temperature equal to or higher than an activation determination temperature when the activation determination unit determines that the temperature of the gas sensor is equal to or higher than the activation determination temperature; an automatic stop detection unit; and a first temperature switching unit that controls electric current supplied to the heater such that the target temperature of the heater is switched to a second target temperature different from a temperature at which blackening is generated in the first solid electrolyte body when an automatic stop is detected.

Abstract: Engine idle control includes commanding a preferred engine idle speed and operating the engine at a mean best torque spark timing, monitoring an engine speed and an engine air/fuel ratio, commanding an injected fuel mass corresponding to the monitored engine speed and the preferred engine idle speed, and commanding a cylinder intake air mass corresponding to the injected fuel mass, the engine air/fuel ratio and a preferred engine air/fuel ratio.

Abstract: Methods and systems are provided for expediting engine spin-down in an engine that is shutdown during engine idle-stop conditions and restarted during restart conditions. In one example, the method comprises, during an automatic engine idle-stop, turning off spark, operating a first cylinder with a rich ratio of air to injected fuel richer than a rich flammability limit, operating a second cylinder with a lean ratio of air to injected fuel leaner than a lean flammability limit, and mixing un-combusted exhaust from the first and second cylinders with exhaust, the exhaust mixture being substantially stoichiometric.

Abstract: Methods and systems are provided for expediting engine spin-down in an engine that is shutdown during engine idle-stop conditions and restarted during restart conditions. In one example, the method comprises, during an automatic engine idle-stop, turning off spark, operating a first cylinder with a rich ratio of air to injected fuel richer than a rich flammability limit, operating a second cylinder with a lean ratio of air to injected fuel leaner than a lean flammability limit, and mixing un-combusted exhaust from the first and second cylinders with exhaust, the exhaust mixture being substantially stoichiometric.

Abstract: An internal combustion engine control apparatus executes an exhaust-valve-early-closing valve timing control in which an exhaust valve is closed before the intake stroke top dead center. The fuel injection timing mode is normally set to an intake-stroke non-synchronized fuel injection mode. However, if the internal combustion engine is idling and the combustion gas temperature is relatively high, the fuel injection timing mode is switched from the intake-stroke non-synchronized fuel injection mode to an intake-stroke synchronized fuel injection mode.

Abstract: An exhaust emission purification system including a controller performing exhaust temperature rise control executing multistage delay injection control for raising the exhaust temperature, if the exhaust gas temperature is lower than a predetermined judgment temperature, and performing particulate matter combustion removal control executing post injection control, if the exhaust gas temperature becomes equal to or higher than the predetermined judgment temperature, when forced regeneration of a diesel particulate filter is carried out. Multistage delay injection control is forbidden when an idle operation state of an internal combustion engine is sustained for a predetermined judgment time and a power take-off is in operating state. The diesel particulate filter is thereby kept in a good state in a vehicle equipped for purifying particulate matter in exhaust gas by executing forced regeneration while avoiding variation in engine speed.

Abstract: A marine engine control system comprising a water jacket, an outlet sensor, and a control module. The water jacket directs a flow of water across a catalytic converter to cool the catalytic converter. The outlet sensor module measures an actual temperature of the water. The control module determines an expected temperature of the water when the catalytic converter is functional.

Abstract: A fuel injection system for a direct fuel injection (DFI) engine is provided. The system includes: injection mode module selects a fuel injection mode to be one of a single injection mode and a dual injection mode during DFI engine idle operation based on a torque request; and a fuel injection command module that commands fuel injection events based on a crankshaft position and the fuel injection mode.

Abstract: The aim of the inventive method is to improve the emission values of an internal combustion engine during idling following a cold start. Said aim is achieved by inferring an adaptive value for the required fuel quantity from a characteristic curve in accordance with the temperature of the internal combustion engine and verifying during continuous lambda regulation whether predetermined adaptation conditions are met. If so, an adaptive value is determined from the parameters of the lambda regulator and the characteristic curve is adjusted according the newly determined adaptive value and the measured temperature of the internal combustion engine.

Abstract: In a combustion engine, the fuel quantity is determined as a function of the inflowing air mass. As a measure for the inflowing air mass, one uses either a main load signal, which is generated by an air-mass flow sensor and represents a measure of the inflowing air mass, or a secondary load signal, which is generated as a function of the degree of throttle of a throttle device in the intake port and of the speed of the combustion engine, to correct the secondary load signal, an air-mass compensation quantity being utilized. The air-mass compensation quantity is generated in operating phases in which the correctness of the main load signal may be assumed, by comparing the main load signal with the secondary load signal.

Abstract: A method and apparatus for trimming a fuel injector located on an engine. The method and apparatus includes modifying an engine speed control, interrupting at least one injection event, monitoring a change associated with an engine speed, and responsively trimming the injector.

Abstract: A system is described for determining degradation of an exhaust gas recirculation system of an internal combustion engine. This method utilizes a combination of parameters to accurately determine degradation of the exhaust gas recirculation system. For example, the system utilizes changes in intake manifold pressure, changes in idle speed control operation, changes in ignition timing, and fueling changes to accurately determine operation of the exhaust gas recirculation system.

Abstract: A fuel injection system in an engine. The system includes a throttle body having a throttle valve, a first sensor, and a control unit coupled to the first sensor. The first sensor measures a sensed throttle valve angle and provides a first output corresponding to the sensed throttle valve angle. The control unit is operable to receive the output generated by the first sensor, operable to compute an expected throttle valve angle, operable to determine an offset between the expected throttle valve angle and the sensed throttle valve angle, operable to determine a corrected throttle valve angle, and operable to compute fueling calculations based on the corrected throttle valve angle. The corrected throttle valve angle is based on the offset and the sensed throttle valve angle.

Abstract: A system and method for detecting an air leak within an engine is provided. The engine includes an intake manifold communicating with an engine cylinder. The method includes measuring an exhaust gas constituent in exhaust gases from the engine when the engine is operating in an idle operating mode. The method further includes determining whether the air leak is present in the engine based on a measured exhaust gas constituent, a first air-fuel correction value, and a second air-fuel correction value.

Abstract: LPG decompressed in a regulator is fed as primary fuel into an intake passage from a carburetor, and is fed as supplementary fuel to the intake passage from an injector. An ECU controls a control variable for the injector to cause an air/fuel ratio detected in an oxygen sensor to be a stoichiometric air/fuel ratio. At idle operation, an optimum state of the control variable with respect to a target value is output from a monitor terminal and is monitored, and an adjusting screw in a slow passage is operated and adjusted to cause the control variable to be the target value. An adjustment range for the control variable is set into two stages through operation of the test terminal. The ECU controls an output pattern of a monitor terminal in individual adjustment ranges at each stage, according to whether or not the control variable falls within the adjustment range.

Abstract: A system and method for detecting an air leak within an engine is provided. The engine includes an intake manifold communicating with an engine cylinder. The method includes measuring an exhaust gas constituent in exhaust gases from the engine when the engine is operating in an idle operating mode. The method further includes determining whether the air leak is present in the engine based on a measured exhaust gas constituent, a first air-fuel correction value, and a second air-fuel correction value.

Abstract: An outboard motor comprises an engine mounted within an engine compartment. The engine comprises an induction system having an induction passage extending between a plenum chamber and a combustion chamber. A throttle valve is positioned along the passage. A bypass passage communicates with the passage at a location between the throttle valve and the combustion chamber. An adjustable valve controls flow through the bypass passage. The adjustable valve can be moved below a first preset throttle angle position and fixed above that preset throttle angle. The engine further comprises a fuel injector. The fuel injection amount is controlled by more than one control map. The control maps determine a fuel injection amount based on at least two sensed engine conditions. Based on throttle angle position, the control scheme determines which control map is used.

Abstract: Even when a reaction delay time of an A/F ratio detection device changes, an A/F ratio controller prevents an A/F ratio feedback control from being disturbed. The controller is programmed to calculate an A/F ratio feedback coefficient by proportional term control and integration term control, and to set length of time for said integration term to be carried out in accordance with an operating state of the engine. It is programmed to calculate the integration term based on the set time and to set a proportional term for shifting said A/F ratio feedback coefficient. It is further programmed to detect a deviation between a first A/F ratio feedback coefficient before the integration term is carried out and a second A/F ratio feedback coefficient after the integration term is carried out and the coefficient is shifted by the proportional term set by said means for setting the proportional term. Based on the detected deviation, the length of time for the integration term to be carried out is corrected.

Abstract: LPG decompressed in a regulator 3 is fed as primary fuel into an intake passage 6 from a carburetor 9, and is fed as supplementary fuel to the intake passage 6 from an injector 11. An ECU 4 controls a control variable for the injector 11 to cause an air/fuel ratio detected in an oxygen sensor 53 to be a stoichiometric air/fuel ratio. In an idle operation, an optimum state of the control variable with respect to a target value is output from a monitor terminal 57 and is monitored, and an adjusting screw 37 in a slow passage 36 is operated and adjusted to cause the control variable to be the target value. An adjustment range for the control variable is set into two stages through operation of the test terminal 56. The ECU 4 controls an output pattern of a monitor terminal 57 in individual adjustment ranges at each stage, according to whether or not the control variable falls within the adjustment range.

Abstract: The fill level of an activated-carbon canister is calculated during the regeneration process in a lean burn combustion engine. While the engine is in idle operation, the fuel mass reduction that is adjusted by a momentum-based idle controller is used as a measure of the hydrocarbon mass flow that is delivered in the regeneration process, when the activating-carbon filter is flushed back into the engine via its intake tract.

Abstract: An arrangement for controlling fuel injection in a diesel engine to prevent generation of smoke even when an accelerator pedal is stamped during idling. A basic amount of fuel injection Qbase is determined from an engine revolution speed Ne and accelerator opening degree Ac. A maximum amount of fuel injection QMAF is determined from the engine revolution speed Ne and an intake air flow rate MAF. It is then determined whether a first condition of vehicle speed being zero and a second condition of accelerator opening degree being not zero both hold true. The maximum amount of fuel injection QMAF is corrected to a smaller value Qlmt when both the first and second conditions are met. In this case, the basic amount of fuel injection Qbase is compared with the reduced maximum amount of fuel injection Qlmt and the smaller one is selected as a target amount of fuel injection Qfnl.

Abstract: A true closed-loop air/fuel ratio control system for an internal combustion engine which uses a cylinder air charge percentage value also known as a cylinder or engine load value, is used to control the air/fuel ratio of said engine in response to the difference of said measured load value and a predetermined optimum load value. This process allows true closed-loop fuel control immediately following a cold or warm engine start without need of a traditional exhaust gas sensor. As this process automatically compensates for all fuel utilized by the engine, even during cold starting and idles, the problems associated with fuel vapor purge systems are eliminated. This process can reduce government regulated emissions from said engine considerably and improve fuel economy a significant percentage particularly when operated net lean of stoichiometric. Elimination of currently required engine hardware for traditional systems can allow for a considerable cost savings.

Abstract: A proportional/integral/derivative control system is provided for controlling the operating parameters of a feedback system according to the difference between a measured value from a component of the system and a target set point. The control system employs a linearization curve having a plateau portion near the target set point. As the measured value approaches the target set point, smaller corrective measures are employed to minimize overshooting and fluctuations. Also, a range is established about the set point wherein no corrective measures are performed.

Abstract: An air-fuel ratio control system for an internal combustion engine includes an air-fuel ratio sensor arranged in the exhaust system of the engine, for detecting the air-fuel ratio of exhaust gases from the engine. An ECU calculates an adaptive control amount, based on an output from the air-fuel ratio sensor, by using an adaptive controller having an adaptive parameter-adjusting mechanism, such that the air-fuel ratio of a mixture supplied to the engine is converged to a desired air-fuel ratio, and controls the air-fuel ratio of the mixture in a feedback manner, according to the adaptive control amount. When a particular engine operating condition in which the adaptive controller can become unstable in operation is detected, the adaptive parameters are initialized according to the adaptive control amount.

Abstract: When feedback control of air/fuel ratio is not being performed in an engine and the engine is idling, the fuel supply amount is increased according to the engine coolant temperature. When feedback control of air/fuel ratio is not being performed and the engine is not idling, the fuel supply amount is decreased according to the engine coolant temperature. Due to this decrease correction, during the time period from when idling operation is terminated directly after starting the engine to when the feedback control of the air/fuel ratio is started, the air/fuel ratio is made lean at an early stage, and the oxygen concentration in the engine exhaust gas is increased, so that the conversion of HC by the catalyst is quickly started.

Abstract: An evaporated fuel treatment device comprising a purge control valve for controllling an amount of fuel vapor fed into the intake passage from a charcoal canister. At the time of restarting a purge action, the purge action is restarted by a low purge rate when the concentration of the fuel vapor to be purged into the intake passage rose to a predetermined concentration while the purge action was stopped and the engine was idling.

Abstract: An air-fuel ratio controller for an internal combustion engine, which controller is capable of: properly correcting an air-fuel ratio after a start-up explosion; preventing inconveniences such as occurrence of an engine stall, a decrease in an engine rotational speed, and a discharge of exhaust gases containing harmful components; and, allocating an idle time-learning value with reference to a rotational engine speed that is obtained at the time of engine start-up, thereby enhancing convenience of use.

Abstract: An air-fuel ratio control device for an internal combustion engine of a vehicle is disclosed. The device controls the air-fuel ratio with a target value which is larger than the stoichiometric air-fuel ratio, as a control center, in an idle condition. The target value is changed to become small when an amount of intake air in an idle condition is larger than a predetermined value.

Abstract: A system for controlling fuel metering for a multi-cylinder internal combustion engine having a feedback loop which has an adaptive controller and an adaptation mechanism coupled to said adaptive controller for estimating controller parameters .theta.. The adaptive controller calculates a feedback correction coefficient using internal variables that include the controller parameters .theta., to correct a basic quantity of fuel injection to bring a detected air/fuel ratio to a desired air/fuel ratio determined earlier from the detected air/fuel ratio by a dead time d'. The dead time d' is properly determined to be corresponding to a time k at which the air/fuel ratio is detected. Alternatively, the dead time may be determined to be longer than the proper value to eventually improve vehicle drivability, or determined to be shorter than the proper value to compensate for insufficient fuel adhesion correction.

Abstract: A fuel control system is provided for use with an internal combustion engine having at least one cylinder, a source of gaseous fuel and an intake passageway for fluidly connecting the air intake to the combustion cylinder. The control system includes a gas flow rate sensor which generates an output signal representative of the fuel flow rate to the engine as well as a mass air flow sensor which generates a signal representative of the mass air flow rate to the engine. A fuel valve is fluidly connected in series between the source of gaseous fuel and the air intake passageway. The fuel valve is actuated by an electrical pulse stream between an open and a closed position so that the duty cycle of the pulse stream is proportional to the amount of fuel supplied to the engine. In response to the fuel flow rate signal, the air flow rate signal and a target air/fuel ratio, the control system generates PID gain scheduling parameters relative to the duty cycle of the pulse stream.

Abstract: A fuel metering control system for an internal combustion engine, having a feedback loop. In the system, the quantity of fuel injection (Tim) to be supplied to the engine (plant) is determined outside of the feedback loop. A first feedback correction coefficient (KSTR) is calculated using an adaptive law, while a second feedback correction coefficient (KLAF), whose control response is inferior to that of the first feedback correction coefficient, is calculated using a PID control law. The feedback correction coefficients are calculated such that the plant output (air/fuel ratio) is brought to a desired value (desired air/fuel ratio). The coefficients are calculated at least in parallel and either of them is selected to be multiplied by the quantity of fuel injection (Ti).

Abstract: An air-fuel ratio control system for an engine for controlling an amount of a fuel mixture to be delivered into a combustion chamber so that an air-fuel ratio of the fuel mixture attains a target air-fuel ratio performs selecting one of a plurality of predetermined target air-fuel ratios according to engine operating conditions, controlling an amount of a fuel mixture so as to attain a selected target air-fuel ratio, and changing a speed at which the target air-fuel ratio is changed from one to another ratio higher with an increase in deviation of the other target air-fuel ratio from the one target air-fuel ratio.

Abstract: An object of the present invention is to carry out air-fuel ratio learning to a high accuracy even in a region such as the idling region wherein the number of acquisitions of air-fuel ratio feedback correction values within a predetermined period is small. Average values A for one fluctuation period of an air-fuel ratio feedback correction coefficient .alpha. are computed and stored in order of computation in a RAM, and an arithmetical mean value B obtained. A weighted average value C of a previous learning correction coefficient .sub.KL and the arithmetical mean value B is then obtained (C=X.multidot.B+(1-X).multidot.K.sub.L). The weighting proportion X is set larger the larger the number of acquisitions of the average value A. C is updated/set as a new learning correction coefficient K.sub.L. In this way, since the updating/setting treatment of the learning correction coefficient K.sub.L is carried out in accordance with the acquisition conditions of .alpha.

Abstract: A warmup fuel amount corresponding to a predetermined heavy fuel is set to control an air-fuel ratio of an air-fuel mixture supplied to an engine during warmup. A correction amount based on a difference between a post-warmup engine speed variation and a first reference value is stored, and a warmup fuel amount decreased by this correction is supplied to the engine on the next startup occasion. In this way the sensitivity of air-fuel ratio control during startup when fuels of different nature are used, is enhanced.

Abstract: An air fuel ratio control system is so arranged to restrain a undesired variation of an air fuel ratio due to an on off control of a canister purge and thereby prevent deterioration of an exhaust performance. When a purge cut valve is closed to cut off the canister purge, the control system changes a feedback air fuel ratio corrective factor ALPHA like a step change to a predetermined initial value EVALP# to meet a leaning change of the air fuel ratio caused by the purge cut. When the purge cut valve is opened to resume the canister purge, the control system meets an enriching change of the air fuel ratio caused by restarting of the purge by producing a step change in the corrective factor ALPHA to an initial value EALPHA.times.KEVAL# determined in accordance with a value EALPHA of the corrective factor ALPHA obtained immediately before the cutoff (KEVAL# is a constant).

Abstract: A fuel metering control system for an internal combustion engine including a feedback loop having an adaptive controller and an adaptation mechanism that estimates controller parameters .theta.. The adaptive controller calculates a feedback correction coefficient that corrects the quantity of fuel injection to bring a controlled variable obtained at least based on an output of an air/fuel ratio sensor, to a desired air/fuel ratio. The convergence speed of the controller parameters are determined by a gain matrix. The gain matrix is determined in response to at least one of the detected engine operating conditions.

Abstract: A method of controlling operation of a compressed natural gas vehicle as a function of a predetermined level of methane in the ambient. Vehicle ignition is turned off when a predetermined level of methane is sensed in the ambient.

Abstract: A gaseous fueled engine and method for controlling the gaseous fuel supply using a feedback control to maintain a stoichiometric mixture under all normal running conditions. The feedback control is discontinued under certain running conditions and control is provided in another method so as to accommodate situations such as starting, conditions when the catalyst associated with the engine is overheated, conditions when the engine is running at wide open throttle to avoid the possibility of catalyst overheating and conditions of rapid deceleration so as to reduce the fuel supply and avoid overly rich exhaust gases when the engine is operating as a pump under extreme deceleration.