Abstract: There is provided a control system for an internal combustion engine, which is capable of properly controlling the amount of exhaust gas recirculation according to a degree of flow rate degradation of an exhaust gas recirculation system and at the same time suppressing progress of the flow rate degradation. The control system has an exhaust gas recirculation system including an exhaust gas recirculation passage for communicating between an exhaust passage and an intake passage, and an exhaust gas recirculation valve for controlling the rate of exhaust gas recirculation to the intake passage via the exhaust gas recirculation passage according to the operation amount of the valve. An ECU cuts off supply of fuel to the engine during deceleration of the engine. An intake pipe absolute pressure sensor detects pressure within the intake passage.

Abstract: An engine control system for a hybrid vehicle having an internal combustion engine and an electric motor as driving force sources, for permitting stopping and restarting of the engine in accordance with predetermined drive conditions. The engine control system includes a fuel cutter for cutting fuel supply to the engine when the vehicle decelerates and an engine speed detector for detecting an engine speed. Stopping of the engine is initiated by cutting the fuel supply by the fuel cutter, and when the engine speed becomes equal to or lower than a predetermined speed, the engine is stopped by operating the motor as a generator and by cutting the fuel supply.

Abstract: A method and an arrangement for operating a drive unit of a vehicle are suggested. A desired value is preset and an actual value corresponding to the desired value is determined. The desired value is filtered in at least one operating situation. At the start of filtering, the filter is initialized with the determined actual value.

Abstract: A device for controlling an engine for a vehicle and an air-conditioning device for a vehicle capable of suitably controlling the blow-out rate of an air-conditioning compressor at the time when the fuel supply has been cut by estimating a load torque of the air-conditioning compressor under a condition of resuming the fuel supply. The air-conditioning device for vehicles according to an embodiment of the invention comprises blow-out rate varying means for varying the blow-out rate of the compressor driven by a vehicle engine, and load torque estimating means for estimating a physical quantity related to the load torque of the compressor under a condition of resuming the fuel supply after the fuel supply has been cut. The blow-out rate of the compressor is changed by controlling the blow-out rate varying means depending upon the estimated value of physical quantity.

Abstract: A method and an arrangement control the drive unit of a vehicle. In this method and arrangement, an rpm limiting to a reference rpm takes place when the demand of the driver is withdrawn. The reference rpm is determined at the start of the withdrawal of the driver command.

Abstract: An apparatus for controlling an internal combustion engine controls an air amount bypassing a throttle valve of the engine. The air amount is decreased according to a difference between an actual rotational speed and a target rotational speed after a completion of a fuel-cut. Therefore, the rotational speed is quickly lowered. The decrease control is finished when the actual rotational speed reaches near a target rotational speed, simultaneously a feedback control is started. The feedback control accurately maintains the actual rotational speed at the target rotational speed. As a result, it is possible to improve fuel consumption and to prevent a stall and a vibration of the engine.

Abstract: In a method for regenerating a NOx storage catalytic converter disposed in an engine exhaust operating with air excess, in operating ranges, the improvement includes storing NOx in the exhaust gas in the converter in a storage phase and catalytically converting the stored NOx in a regeneration phase. The signal of the NOx sensor disposed downstream of the converter is detected in the operating range of the overrun fuel cut-off and an average/minimum value is formed from the individual measured values. The average/minimum value is stored as an offset value of the sensor signal. In operating ranges beyond the engine overrun fuel cut-off, the signal of the NOx sensor is detected and the offset value is taken into account when the signal is processed further, in that the offset-corrected signal is compared with a threshold value. In the event that the threshold value is exceeded, a regeneration phase of the converter is initiated.

Abstract: This invention relates to a procedure for analyzing and influencing the driveability of motor vehicles, including the following steps: Conducting tests on a real vehicle to obtain measurement variables describing its driveability; Continuous monitoring to check whether at least one of a number of predefined trigger conditions is fulfilled, i.e., whether a certain set of variables takes on certain values; If the trigger condition is fulfilled, computation of a profile of several ratings representing vehicle driveability from one or more measured values, using predefined functional relationships.

Abstract: An engine control method for improving air-fuel ratio control controls airflow when fuel injector limits are reached. The method includes a transient fuel model to calculate a required fuel injection amount based on actual cylinder air charge and feedback from an exhaust sensor. When the required fuel injection amount is outside an operable range, for example, less than zero, airflow is controlled to prevent deviations of exhaust air-fuel ratio. Otherwise, airflow is controlled to provide a desired engine torque. Alternatively, a minimum allowable airflow is determined based on a minimum achievable fuel flow. Then, airflow is prevented from falling below this minimum allowable airflow. The method is particularly useful in preventing rich excursions during rapid decreases in desired engine torque, such as during a driver tip-out.

Abstract: A reciprocating internal combustion engine using poppet valves, valve timing control and fuel injection, cuts off fuel during engine deceleration and controls valve timing such that charge is trapped in the engine cylinders while the fuel is shut off. As such, catalytic after treatment devices are neither cooled nor saturated with oxygen and engine fuel economy is improved.

Abstract: An engine operation control device which sets higher than the target revolution speed for the idling state the target revolution speed of the engine immediately after the engine operation has shifted to the idling state, to prevent troubles caused by bubbles in the working fluid. When the engine operation shifts to the idling state at time t2, the count value Cnt of the idling counter starts counting. When the count value Cnt reaches the set value Cnt1, the revolution speed correction amount And is added to the target revolution speed for the idling state. The correction amount And progressively decreases with the elapse of time after the engine operation has shifted to the idling state.

Abstract: A system for purifying exhaust gas of an internal combustion engine having a NOx reduction catalyst (NOx absorber) installed in the exhaust system of the engine which absorbs NOx in the exhaust gas generated by the engine in a lean environment where a lean fuel mixture is supplied and desorbs to reduce the absorbed NOx in a rich environment where a rich mixture is supplied. In the system, the rich fuel mixture is supplied for a period immediately before cutoff. With the arrangement, the NOx reduction catalyst desorbs the absorbed NOx and is regenerated to absorb NOx sufficiently. At the same time, the NOx reduction catalyst is regenerated from sulfur poisoning, thereby preventing the NOx purification efficiency from being degraded.

Abstract: A fuel control device for cylinder injection type internal combustion engines which is capable of cutting off fuel supplying to a combustion chamber depending upon an operating state of the engine and suitable for use in cylinder injection type engines, in which a compression stroke mode can be selected for the purpose of enabling shifting to fuel cutoff and shifting to fuel injection from cutoff without incurring shock of switching in the engine.

Abstract: A setpoint torque is determined from a torque factor, a maximum torque and a minimum torque. The torque factor is derived from a pedal value and a rotational speed. The maximum and minimum torques are determined as a function of the rotational speed, a loss torque and engine performance parameters. The loss torque is determined as a function of the rotational speed and the performance parameters.

Abstract: An engine control system for an automobile engine of, for example, the type which injects fuel directly into an combustion chamber (16) and executes a fuel-cut control under a specified engine operating condition establishes a stratified charge combustion mode and a homogeneous charge combustion mode selectively according to engine operating conditions following termination of the fuel-cut control and shuts off nearly completely an engine throttle valve (28) during execution of the fuel-cut control and opens the engine throttle valve (28) so as to variably control an amount of intake air passing through an intake passage (24) into the combustion chamber (16) before the stratified charge combustion mode is established following termination of the fuel-cut control.

Abstract: A method of controlling fuel supply during a deceleration fuel shutoff mode includes determining the amount of oxygen stored in the catalyst or the temperature thereof and intermittently supplying fuel to the engine such that the fuel reacts in the catalyst to reduce excess oxygen therein.

Abstract: An air-fuel ratio control system for an internal combustion engine includes an ECU which cuts off fuel supply to the engine at deceleration thereof, measures a fuel cut-off period over which the fuel cut-off means cuts off fuel supply to the engine, and enriches the air-fuel ratio of a mixture supplied to the engine to a degree dependent upon the measured fuel cut-off period, at the restart of fuel supply to the engine immediately after termination of cutting-off of fuel supply to the engine.

Abstract: Power to the driven wheels is increased when the motor vehicle is traveling around a curve and the driver suddenly releases the gas pedal. A sudden release of the gas pedal is recognized when the rate of change of pedal position or the engine speed exceeds a threshold on the negative direction, or when the speeds of the driven wheels are less than the speeds of the non-driven wheels.

Abstract: A fuel injection amount in an engine is determined based on a cylinder air volume equivalent fuel injection amount and a wall flow correction amount. The fuel injection amount is also decreased in an initial injection when fuel injection is restarted after it is has been stopped. In this way, sudden torque increases are suppressed without causing a loss of engine rotation speed when fuel injection is restarted after it has been stopped.

Abstract: An internal combustion engine is constantly monitored for overrun mode. When the overrun mode is detected, the fuel injection to the cylinders is shut off. After the shutoff of fuel injection has been accomplished, the ignition is shut off as well, but only after the (complete) degradation of a fuel wall film in the intake tube. This increases the service life of the ignition system (ignition coil, ignition end stages, spark plugs) and reduces the consumption of electrical energy.

Abstract: The invention is directed to a method and an arrangement for controlling the torque of an internal combustion engine. A desired value is determined while considering the engine speed starting from a desired torque value to increase the engine torque during overrun operation when the engine brake torque is too high. With this desired value, the torque of the engine is adjusted in the sense of approaching the desired value.

Abstract: A control system for an internal combustion engine determines whether or not at least one of fuel cut which is cutting-off of supply of fuel to the engine and decreased fuel supply which is supplying of fuel to the engine in a decreased amount for deceleration of the engine has been started, and whether or not purging of evaporative fuel into an intake passage of the engine by an evaporative emission control system of the engine was carried out within a first predetermined time period before the at least one of the fuel cut and the fuel supply reduction for deceleration of the engine has been stated. The amount of auxiliary air supplied to the engine via a secondary intake air passage bypassing a throttle valve arranged in an intake passage of the engine is increased over a second predetermined time period after the at least one of the fuel cut and the decreased fuel supply for deceleration of the engine has been started.

Abstract: A throttle valve full-closure detecting system for an internal combustion engine which is capable of surely detecting a fully closed state of a throttle valve and further of preventing the occurrence of troubles when an accelerator pedal is released from the state where the driver lightly places his foot thereon. The throttle valve full-closure detecting system comprises a full-closure detecting unit 6 for detecting the fully closed state of the throttle valve 1, and a throttle sensor 5 for sensing a throttle opening degree .theta. of the throttle valve 1.

Abstract: A valve timing control device for an internal combustion engine comprises a variable valve timing mechanism capable of varying a valve overlap period. Fuel injection can be stopped in at least one predetermined engine operating condition and an optimal value of the valve overlap period in the current engine operating condition can be determined, on the basis of current engine speed, load, and temperature. The variable valve timing mechanism can be controlled such that the valve overlap period becomes larger than the optimal value when fuel injection is stopped. Accordingly, in the idle condition when the engine has not warmed up, intake air is heated sufficiently, by the valve overlap period, to more than the optimal value and an engine stall at this time is completely prevented by increasing the amount of intake air.

Abstract: A robust engine fueling control is provided for assuring neutral attainment in a vehicular automated mechanical transmission system (10) having a manually controlled master clutch (16). Upon sensing a requirement for a shift into transmission neutral, the disengaging jaw clutch members (134A/142A) are constantly urged into a disengaged position, fuel is caused to decrease to idle (302), and then fuel is blipped by increasingly larger amounts (304, 306, 308) until neutral is sensed.

Abstract: The invention involves stopping the operation of an internal combustion engine, when actual vehicle deceleration is detected after a vehicle deceleration operation. Alternatively, under conditions wherein it is possible to shut off fuel supply at the time of the deceleration operation, the invention involves stopping the operation of the engine by shutting off the fuel supply to some cylinders, and then shutting off the fuel supply to all cylinders when actual vehicle deceleration is detected. Since the fuel supply to the engine is timed to be shut off when the vehicle is decelerated, the speed is reduced smoothly without an accompanying large torque change. Thus, vehicle ride comfort and fuel consumption can be improved.

Abstract: An apparatus for regulating power produced by a motor vehicle engine is disclosed. The apparatus cooperates in association with throttling valves and engine power moderating devices. The apparatus has first detecting device for detecting the operating condition of said engine. The detecting device generates a signal in response to detected engine condition. The apparatus further has a second detecting device for detecting a malfunction in the throttle valves and generates a signal in response to the detected malfunction. A controller functions responsive to the signals generated by the first and second detecting devices for generating first and second engine power values representative of range of engine power in accordance with said operating condition prior to the occurrence of malfunction of the throttle valves. The controller controls the engine power moderating device to moderate engine power based on the first and second engine power values.

Abstract: In order to control wheel spin in a vehicle driven by an internal combustion engine, a spin calculator determines the amount of wheel spin and compares this with a target value. If the target value is exceeded, an engine controller reduces engine output demand, for instance by reducing the opening of a throttle. A fuelling controller forms a threshold value which is inversely dependent on the difference between the reduced engine output demand and the actual engine output demand. When the wheel spin exceeds the threshold value, the controller cuts off the supply of fuel for a predetermined pattern of engine fire events.

Abstract: An air-to-fuel ratio control system optimally controls an air-to-fuel ratio of an internal combustion engine according to various engine operating conditions, and aims at assuring quick air-to-fuel ratio control and preventing erroneous operation of the engine. With this control system, a corrective amount of fuel to be supplied is determined according to a deviation .DELTA.(A/F) of a measured air-to-fuel ratio (A/F).sub.i and a target air-to-fuel ration (A/F).sub.OBJ. This corrective amount of the fuel is kept in an allowable range defined by limits K.sub.LMIN and K.sub.LMAX, or K.sub.RMIN and K.sub.RMAX. Therefore, the engine is supplied with the fuel which is controlled according to a target fuel amount LT.sub.INJ determined by the correct fuel amount. The control system is responsive to various engine operating conditions, and protects the engine against troubles, damage and interruption, and prevents deterioration of exhaust gases.

Abstract: In an automotive type engine having an air bypass valve controlling a portion of the air flow to the engine, decelerations are controlled in a manner to minimize or eliminate the conventional large feedback negative torque impulse to the operator usually experienced when fuel is shut off. The air bypass valve is closed down, in response to correct decel conditions, to an air flow level below that scheduled to establish the normal idle speed condition. The positive engine combustion torque is decreased so that the magnitude of the ratio between it and the engine negative torque becomes small. Immediately following fuel shut-off, the bypass valve is reopened to return the air flow to that level establishing the set idle speed condition upon resumption of fuel flow.

Abstract: A bypass air flow rate control apparatus has an idle speed control valve for continuously adjusting an air flow rate and an on-off control valve for allowing and shutting off an air flow passing therethrough. When an atmospheric pressure sensor detects that the atmospheric pressure is lower than a predetermined value, in other words, the density of intake air is lower than a predetermined value, the on-off control valve and the idle speed control valve are switched over. The air flows through the on-off control valve by an amount corresponding to the air flow rate reduced in the idle speed control valve. The valve switching over operation is performed when one of the following three conditions is satisfied: the engine is generating no torque, in other words, the engine is in a fuel cut operation; a load larger than a predetermined load value is applied; and the engine is accelerated at a rate equal to or greater than a predetermined value.

Abstract: An engine governor system includes an electronic governor which controls the fuel supply to an engine in response to an throttle signal supplied by a throttle potentiometer which coupled to a throttle lever. A circuit is connected between the throttle potentiometer and a potential source. The circuit includes a normally closed foot-operated deceleration switch connected in parallel with a first variable resistor, both connected in series with a third variable resistor. Closing the foot-operated switch will reduce the throttle signal by an amount controlled by the adjustment of the first variable resistor. The maximum possible throttle signal can be controlled by the adjustment of the second variable resistor.

Abstract: When the throttle of a vehicle engine is released by the vehicle operator of a vehicle having an automatic transmission, the slip of the automatic transmission is measured and the airflow of the engine is trimmed as a function of the measured slip to establish a desired drive-on feel of the vehicle during coastdown.

Abstract: A method for controlling an internal combustion engine is proposed, in particular in conjunction with control systems for engine power, in which, in order to avoid potentiometer failures due to deposits of insulating abraded material on the potentiometer track due to the movement of a positioning component, in particular a throttle flap, in overrun operation, with released accelerator pedal and above a pregiven resume engine speed where there is fuel cutoff, the positioning component is briefly moved out of its fixed position or is closed beyond its pregiven idle position. On reaching a certain position for upon renewed fuel supply due to the engine speed falling below the resume engine speed, the positioning component is abruptly reset to its fixed position.

Abstract: A system and method for controlling an operation of an internal combustion engine of a vehicle having an automatic transmission in which at least one of predetermined fuel supply recovery engine revolution speed or predetermined fuel supply cut-off engine revolution speed is varied during the engine deceleration condition according to a state of operation of the automatic transmission. In the first preferred embodiment, a downshift operation of the automatic transmission is detected. In the second preferred embodiment, an overrun clutch solenoid is turned on (energized). In the latter case, both fuel supply recovery and fuel supply cut-off engine revolution speeds are set to higher values than those when the clutch solenoid is turned off (deenergized).

Abstract: A method is described for controlling the injection of fuel in a direct injected, multi-cylinder internal combustion engine, to smooth transients in engine output torque associated with a deceleration fuel cut-off mode of engine operation. This is accomplished by detecting engine operating conditions that call for the initiation of a transition associated with the decelaration fuel cut-off engine operating mode. In response to the detected operating conditions, a transitional period is initiated, during which the injection of fuel into a varying portion of engine cylinders is then interrupted. When the transitional period is associated with entry into the deceleration fuel cut-off mode, the injection of fuel to a progressively increasing number of cylinders is interrupted. When the transitional period is associated with recovery from the deceleration fuel cut-off mode, the injection of fuel to a progressively decreasing number of engine cylinders is interrupted.

Abstract: The disclosure describes a method of avoiding an excessive drag torque for motor vehicles. When the accelerator pedal is released, an amount of fuel is supplied to the engine which is approximately under zero-load and which is gradually reduced over time. The occurring change of the rotational speed is monitored. When a certain rotational speed change is exceeded per time unit, the amount of fuel is gradually increased over time until a certain positive rotational speed change is recognized. Then, there is a switch-back to reducing the amount of fuel. The procedure is repeated until the vehicle has reached an operational condition with a constant rotational speed.

Abstract: A method is described for increasing engine braking, when a crankcase scavenged two-stroke engine is operated in a deceleration fuel cut-off mode. In response to the detection of operating conditions indicating engine operation in the deceleration fuel cut-off mode, the quantity of air inducted into the engine is decreased, for a predetermined period of time. After this period of time elapses, the quantity of air inducted into the engine is then increased. This is preferably accomplished by regulating the degree of opening of a throttle valve disposed within the engine air intake system. The initial closing of the throttle valve restricts air flow through the engine for a predetermined time, to maintain efficient catalyst operating temperatures in the engine exhaust system. During extended operation in the deceleration fuel cut-off mode, the throttle valve is opened, after the lapse of the predetermined time, to increase the quantity of air inducted by the engine.

Abstract: There is proved a driving force control system which comprises device for measuring operating state of the vehicle brake system and generating an output signal, and device for controlling a driving force upon a predetermined condition being fulfilled after the output signal has indicated a predetermined operating state of the vehicle brake system.

Abstract: In a cruise-control system mounted on an automobile after a cruise-control mode has been established, a microcomputer prevents the electronic fuel-injection system of the automobile from cutting off the supply of fuel to the engine. This prevents the velocity of the automobile from surging when the automobile does down a hill. Another embodiment of a cruise-control system has an electronic fuel-injection system and an actuator that controls the opening of the throttle valve. When the opening decreases to a small opening slightly larger than the opening at which the fuel-injection system stops supplying fuel to the engine, the fuel-injection system maintains the valve at the small opening.

Abstract: A fuel injection control device in which the supply of fuel into the engine cylinder is stopped at the time of deceleration, and a rich time of the air-fuel mixture is calculated when the supply of fuel is stopped. If the rich time becomes relatively long, the accelerating increasing rate of the amount of fuel is increased, and if the rich time becomes relatively short, the accelerating increasing rate of the amount of fuel is reduced.

Abstract: In an air-fuel ratio feedback control system including at least one air-fuel ratio sensor downstream of a catalyst converter provided in an exhaust gas passage, an actual air-fuel ratio is controlled in accordance with the output of the downstream-side air-fuel ratio sensor. When at least one of the air-fuel ratio feedback control conditions for the downstream-side air-fuel ratio sensor is not satisfied the controlled air-fuel ratio is made an air-fuel ratio by an open loop control, while all the air-fuel ratio feedback control conditions for the downstream-side air-fuel ration sensor are satisfied the controlled air-fuel ratio is made the stoichiometric ratio (.lambda.=1) in accordance with the output of the downstream-side air-fuel ratio sensor.

Abstract: A controller controls an engine in cooperation with an automatic transmission which is automatically locked when an operating speed of the engine is higher than a previously established transmission lockup speed. The controller includes an engine power increasing device when an operating engine speed becomes lower than the transmission lockup release speed. The transmission lockup release speed is corrected according to deceleration rates.

Abstract: A driving wheel slip control system for a vehicle equipped with an internal combustion engine, in which a decelerating condition of the engine is detected, a slip state of the driving wheels is detected, and the torque of the driving wheels is reduced in response to the detected slip state of the driving wheels. The torque reduction is inhibited irrespective of the detected slip state when the decelerating condition of the engine is detected. The engine is determined to be in the decelerating condition when the engine is in a region where the air-fuel ratio of a mixture being supplied to the engine is to be controlled to a value leaner than a stoichiometric ratio.

Abstract: A two-stroke engine has a scavenge pump provided in an intake passage, a bypass around the scavenge pump and a fuel injector provided for injecting fuel in a cylinder of the engine. A valve is provided in the bypass so as to close the bypass. When deceleration of a vehicle is detected, the valve is closed and the fuel injection from the fuel injector is stopped.

Abstract: A fuel supply control method for an engine having a fluid torque converter with a clutch for mechanically connecting the input and output sides of the fluid torque converter wherein the clutch is engaged and the fuel supply to the engine is stopped during speed reduction when the engine speed or the vehicular speed is over a predetermined value under a no load condition of the engine, such as during deceleration from a high speed. In the present method the clutch is released first at a predetermined speed and then the fuel supply to the engine is restarted when the speed, either engine speed or vehicular speed, drops below the first predetermined speed.

Abstract: Safety device for motor vehicles utilizes a cam-like plate and linkage to prevent accidental acceleration of a motor vehicle when disengaging the vehicle's shift lever from the park or neutral position. The apparatus employs an electrical circuit to detect the position of the shift lever and the activation and deactivation of the brake foot pedal. Only after placing the vehicle into any drive position other than park or neutral, and releasing a pedally operated brake pedal, will the linkage permit the throttle of the motor vehicle to move from its idle position to any position selected by the operator upon later application of an operating force to the accelerator pedal. In this manner, the operator is assured that the motor vehicle will not accidentally be caused to lurch forward or backward at high speed.

Abstract: A constant-speed control device for a vehicle including a fuel cut device and a suspending device which suspends a fuel cut operation. An actuator is provided for controlling a throttle valve so that the vehicle runs at a constant speed. The fuel cut device carries out a fuel cut when the degree of opening of the throttle valve is smaller than a predetermined value. The suspending device suspends operation of the fuel cut device until the vehicle speed becomes higher than a target value by a predetermined value.

Abstract: A fuel control system for providing a dashpot operation at release of an accelerator pedal of a motor vehicle. A bypass is provided around a throttle valve of an engine and an idle speed control valve is provided in the bypass, for controlling air passing in the bypass. When the accelerator pedal of the motor vehicle is released, an idle signal is produced. In response to the idle signal, idle speed control valve is gradually closed. After a set time, fuel supply by a fuel injector is cut off.

Abstract: In a device on a motor vehicle with an internal combustion engine as the drive source and an accelerator pedal and transmission means for controlling the power of the internal combustion engine a switch activated when the accelerator pedal is actuated is provided in the power control system, which switch, in the non-activated state, prevents the internal combustion engine from delivering power exceeding its idling power. If the internal combustion engine is provided with an overrun cut-off for interrupting the fuel supply during overrun operation, the switch can be the idling switch of the overrun cut-off.