Abstract: An automatic speed control apparatus for controlling the running speed of a vehicle at a constant set speed includes an auxiliary intake passage providing direct communication between portions of a main intake passage upstream and downstream from a throttle valve so as to bypass the throttle valve, an auxiliary intake air valve adapted for controlling the flow rate of air in the auxiliary intake passage, and a fuel supply cut-off means for suspending the supply of fuel to the engine from a moment at which a fuel supply cut-off condition is met, which requires the throttle valve to be set at the minimum opening position and the engine speed to be higher than a predetermined fuel supply cut-off engine speed, until the moment at which a predetermined fuel supply recovery condition is met. An actuator for actuating the throttle valve is controlled so as to vary the degree of opening degree of the throttle valve and enable the vehicle to run at the constant set speed.

Abstract: An air fuel ratio control apparatus, performs fuel decrease compensation during deceleration with respect to an air fuel ratio upon detection of a returning operation of a throttle valve. To avoid variations in torque which detract from a smooth ride, fuel decrease compensation is prohibited under the conditions that the opening of the throttle valve is in a full opening region and the amount of return movement of the throttle valve per unit time is equal to or less than a preset valve.

Abstract: An idle switch is provided to respond to release of an accelerator pedal of a motor vehicle, for producing an idle signal. A large increment of the engine speed after the production of the idle signal is detected and an engine speed increase signal is produced. The increment is compared with a predetermined value and an immediate cutoff signal is produced when the increment is larger than the predetermined value. In response to the immediate cutoff signal fuel supply is immediately cut.

Abstract: A system for cutting off the supply of fuel to an automobile engine in a specific operating region within the deceleration region of the engine determines whether the engine transmission is manual or automatic. The system has for each of the manual transmission and automatic transmission, a fuel cut-off rpm at which the supply of fuel is cut off when sensed engine rpm is greater than the fuel cut-off rpm, and a fuel restoration rpm, which is set to be less than the fuel cut-off rpm, at which the fuel supply is resumed when sensed engine rpm is less than the fuel restoration rpm.

Abstract: A method of operating and exhaust-gas-turbocharged, low-compression multi-cylinder Diesel-cycle internal combustion engine that has a first cylinder group which operates over the full load range, and a second cylinder group which is cut out during starting and in the idling and part load ranges but is cut in in the remaining load range, each cylinder group having associated with it a turbocharger with associated charge air pipe, the charge air pipes being interconnected by a pressure equalizing system.

Abstract: An engine used for automobiles, wherein the gases are discharged from the cylinder after purification, thereby reducing the air pollution problems, and the engine secures a strengthened engine brake by utilizing the pneumatic force as a restraint on the piston.

Abstract: The invention is directed to a method for the adaptation of mixture control for an internal combustion engine which is set up from operating quantities of the engine such as throttle flap angular position .alpha. and rotational speed n. The characteristic field provides a precontrol quantity governing the quantity of fuel to be metered or injected. The method includes the steps of: influencing the precontrol quantity by at least one adaptively changeable corrective quantity (structural adaptation, global adaptation); detecting the negative change velocity (-d.alpha./dt) of the throttle flap position angle (.alpha.); comparing the negative change velocity (-d.alpha./dt) with a predetermined threshold value [-d.alpha./dt(SchAd)]; evaluating a quantity (.DELTA..alpha.) indicative of the throttle flap change in angular position when the threshold value [-d.alpha./dt(SchAd)] is exceeded, the quantity (.DELTA..alpha.

Abstract: A method for controlling an air/fuel ratio of an internal combustion engine. The fuel supply is performed normally by a feedback control operation for controlling the air/fuel ratio of the mixture toward a target air/fuel ratio in accordance with an oxygen concentration in an exhaust gas of the engine. A fuel cut operation under a predetermined condition includes a step for detecting a transition from the fuel cut operation to resume the fuel supply, and a step for shifting, for a time period after a detection of the transition, the target air/fuel ratio of the feedback control to a lean side with respect to a target air/fuel ratio value to be used after the elapse of the time period.

Abstract: The fuel supply to an internal combustion engine is decreased when the engine is in an operating region wherein the intake passage pressure is lower than a first predetermined value. The first predetermined value is corrected in response to detected atmospheric pressure encompassing the engine. Further, the fuel supply to the engine is interrupted when the engine is in a second operating region wherein the intake passage pressure is lower than a second predetermined value, which is lower than the first predetermined value. The second predetermined value is corrected in response to the detected atmospheric pressure, together with the first predetermined value.

Abstract: An air/fuel ratio control system for an internal combustion engine includes an oxygen concentration sensor for sensing the oxygen concentration in the exhaust gas of the engine, and a correction value setting device which determines a correction value corresponding to an output signal of the oxygen concentration sensor obtained when the fuel cut operation of the engine has continued for more than a predetermined time period. The output signal of the oxygen concentration sensor is corrected by the correction value during the engine operation other than the fuel cut operation.

Abstract: The disclosure is directed to a control device for an internal combustion engine for a motor vehicle such as an automobile or the like, having a control valve disposed in a by-pass passage for opening and shutting the by-pass passage which communicates the upstream side and the downstream side of an intake passage by by-passing a throttle valve, in which the engine speed in idling operating condition is controlled to a target speed. This control device is characterized in that the ignition timing is rather advanced than ordinary idling ignition timing during a certain period from the instance when the engine has entered into the idling operating condition after having received a signal detecting the idling operating condition of the engine.

Abstract: A system for automatically controlling the idling speed of an internal combustion engine, comprising a valve, for supplying an adjustable quantity of additional air, and means for controlling the setting of the valve as a function of the detected speed of the engine and comparison with an idling speed range, and as a function of the detected pressure in the intake manifold and comparison with a value equivalent to the required air supply.

Abstract: A method for controlling the operating characteristics of an internal combustion engine is disclosed. An injection signal for metering fuel and an idling charge signal for the supply of idling air are present. Engine overrun is also recognized in this method. To diminish the bucking ordinarily occurring during the transition to overrun, after the overrunning is recognized the supply of idling air is first reduced, and then the fuel metering to the engine is interrrupted. This affords the advantage that the transition to the overrun mode of operation occurs precisely at the time when the engine has the least possible torque. An analogous procedure is described for the resumption of normal operation following overrun.

Abstract: In a method of controlling an air-fuel ratio for an internal combustion engine, a control section feedback-controls an electronically controlled carburetor in response to a signal from an O.sub.2 sensor which detects the concentration of O.sub.2 in the exhaust gas. When the O.sub.2 sensor outputs a rich signal for a predetermined time period after the air-fuel ratio is leaned upon deceleration of the engine, the rich air-fuel ratio is instantaneously and forcibly leaned by the control section in order to rapidly return it to a proper value. Thereafter, ordinary feedback control is resumed. With this method, the quantity of harmful exhaust gas components such as CO or the like can be reduced without making the operational performance of the engine deteriorate.

Abstract: A system and method for controlling a fuel supply to a vehicular internal combustion engine, in which a predetermined threshold value at which a fuel supply cutoff zone of the engine is initiated is varied so as to provide an optimum range of the fuel cutoff zone according to a magnitude of the engine deceleration and the variation of the predetermined threshold value is learned and stored for the subsequent use as the predetermined threshold value to cope with a characteristic change of the system including the engine and engine output power transmission. When the magnitude of the engine deceleration is large, the predetermined threshold value is increased so as to avoid repetition of fuel supply cutoff and fuel supply resumption which affects adversely the engine driveability. When the magnitude is small, the predetermined threshold value is decreased i.e., made closer to another predetermined threshold value at which a fuel supply recovery is carried out so as to extend the fuel supply cutoff zone.

Abstract: In an internal combustion engine, a base fuel amount is calculated, and a synchronous fuel amount to be supplied to the engine is calculated in accordance with the base fuel amount. Further, an air-fuel ratio deviation is calculated when the engine is in an acceleration state, and an asynchronous fuel amount is calculated for the transition of the engine from a fuel cut-off state to a fuel cut-off recovery state in accordance with the calculated air-fuel ratio deviation.

Abstract: An energy conserving system for use with vehicles with an internal combustion engine and friction brakes includes a first valve in the air/fuel feed to the engine, a second valve in the exhaust line, a tank for pressurized air, and conduits between the tank and the valves. Actuation of a control system enables a first sensor to determine whether the brakes are being applied which opens the second valve to divert exhaust to the tank. During startup, the compressed air with or without fuel is used to reciprocate the pistons for a limited period after which fuel/air mixture feed at atmospheric pressure is commenced for normal engine operation. During engine startup, the brake sensor is not activated; and fuel supply to the engine is only cut while braking. However, fuel can be mixed with pressurized air from the pressure tank at any time depending upon accelerator position to make the engine work as a compressed air supplied engine or as a turbo combustion engine.

Abstract: In an internal combustion engine wherein feedback control of the air-fuel ratio is carried out in accordance with the concentration of a specific composition in the exhaust gas, so that the air-fuel ratio is close to an predetermined target air-fuel ratio on the lean side with respect to the stoichiometric air-fuel ratio, the rate of fuel cut-off for a definite time period is calculated. When the rate of fuel cut-off is larger than a predetermined value, the air-fuel feedback control is stopped.

Abstract: An electronically controlled fuel injection apparatus in which opening degree of a throttle valve or throttle aperture is sampled periodically at a predetermined time interval to detect change in the throttle aperture for determining deceleration. Upon every determination of the deceleration, a correcting quantity is accumulatively determined so that deceleration is corrected for compensating delay in the control of fuel injection in dependence on magnitude of change in the throttle aperture. An improved engine performance and optimum air-fuel ratio control can be accomplished.

Abstract: A system has an accelerator pedal switch for sensing the deceleration of a motor vehicle, an electronic circuit operative to cutoff fuel at deceleration of the motor vehicle in order to reduce fuel consumption of an engine. When the switch closes by the failure of the switch, the electronic circuit operates to continue the supply of fuel in order to prevent the stall of the engine.

Abstract: A device molding a link member interconnecting an actuator to arms fixed onto valve shafts of rotary valves arranged in gas passages. The link member includes a control rod connected to the actuator and a plurality of plate springs which extend from the control rod and are outwardly bent. The outer ends of the plate springs are pivotally connected to the tips of corresponding arms.

Abstract: An internal combustion engine provided with a device for cutting fuel during deceleration and a purge system for selectively opening and closing a fuel passageway from a charcoal canister to an intake system of the engine in accordance with the operating condition of the engine. The purge system is operated so that the passageway is closed when the fuel is cut, and the purge system is operated so that the passageway is opened and closed in accordance with the operating condition of the engine when the engine is in a deceleration condition other than the particular condition where the fuel is cut.

Abstract: A device for disconnecting the feed of fuel to an internal combustion engine with an injection pump during the coasting of an automotive vehicle comprises a solenoid valve for disconnecting and reconnecting the feed of the fuel. The valve is controlled by the decrease in the speed of the internal combustion engine. In order to adapt the disconnect threshold and the reconnect threshold of the feed of the fuel to the characteristic curve of the internal combustion engine at little expense but nevertheless with a large saving in fuel, the solenoid valve is connected to an outlet line of an idle-speed controller which is provided for the same internal combustion engine. The time response of the controller has at least a differential portion in addition to a proportional portion, but possibly proportional, integral and differential portions. The adaptation of the time response portions to the dynamic behavior of the internal combustion engine is the same as for the control for the idling speed.

Abstract: An engine control microprocessor transient interrupt system is provided wherein an engine throttle position sensor provides a throttle position input signal to a microprocessor which developes engine control output signals in response thereto. The throttle position sensor also provides an input signal to a transient detector external to the microprocessor which provides an interrupt signal to the microprocessor in response to the rate of change of throttle position exceeding a threshold. In response to the interrupt signal, the microprocessor provides a disable signal which disables the external transient detector, and then the microprocessor monitors the rate of change of engine throttle position to determine the end of the throttle position transient condition and enables the external transient detector in response to the end of the transient condition.

Abstract: A fuel control system for a motor vehicle has an accelerator pedal switch for detecting deceleration of the vehicle, an engine speed detecting circuit for detecting high engine speed and low engine speed. The system has gate circuits responsive to the outputs of the accelerator pedal switch and engine speed detecting circuit at high engine speed for producing a signal for cutting off fuel supplied to cylinders of the engine, and to responsive to the output of the engine speed detecting circuit at low engine speed for intermittently supplying the fuel and thereafter for continuously supplying the fuel.

Abstract: A system for regulating rotary speed of an internal combustion engine includes an idling volumetric efficiency or charge regulating system and an overrun or push cutoff system to maintain a minimum rotary speed of the engine during important operational modes. The system is provided with means which eliminate undesired overrun cutoff of intentionally increased rotary speeds of the engine induced by the idling volumetric efficiency regulating system. The actual value of the control signal produced by the regulating system is compared with a limit or threshold value and after the threshold is exceeded the function of the overrun cutoff device is blocked. The regulating system includes a PID regulator which in combination with the circuit of this invention produces a dynamic behavior of the resetting rotary speed of the overrun cutoff function.

Abstract: The invention is directed to an apparatus for controlling the overrun mode of operation of an internal combustion engine in dependence on the instantaneous rotational speed and a threshold characteristic of a resume speed. A throttle valve position sensor, a speed comparator and an evaluation circuit for determining a fuel supply cutoff or a fuel metering signal are provided. Means responsive to engine speed or actuable at the operator's discretion permit the circuit to be held in a state in which the overrun cutoff signals are suppressed. If these means are speed-dependent, a dynamic suppression for a predetermined period of time results; the means utilized for suppressing the overrun cutoff function may also be actuated in response to external driving situations or in response to the conditions of other components of the vehicle.

Abstract: A process whereby fuel injection is interrupted in response to detection of a deceleration and injection is again ordered when a threshold linked to the engine speed is reached. The engine speed (N) or period of rotation (T) is measured from consecutive equal intervals or angles of rotation. A difference (.DELTA.T, .DELTA.N) is then computed between the value of the last measured speed or period and the value seen through a high-pass filter of the speed or period measured at the preceding interval. This difference (.DELTA.T, .DELTA.N) is compared with a fixed threshold (S) and if an engine deceleration condition is detected, fuel injection is again ordered when the difference (.DELTA.T, .DELTA.N) is greater than the threshold (S).

Abstract: The minimum fuel injection time is on electronically controlled fuel injection engine is set in relation to the running condition of the engine. For example, in shift change, when the throttle valve is in the idling angle and the revolution speed of the engine is high, the minimum fuel injection time is set to a small value to improve the efficiency of fuel consumption. Also, at the completion of fuel cut-off when the revolution speed of the engine is low, the minimum fuel injection time is set to a large value to improve the driveability of the vehicle.

Abstract: A method and an apparatus for overrunning control in an internal combustion engine are proposed, which operate with an overrunning cutoff and the reestablishment rpm of which is dependent on rpm and on time. At the onset of overrunning, a higher reestablishment rpm is selected, and once the rpm falls below a predetermined rpm value the reestablishment rpm is reduced according to a time function to a lower threshold value. The method may be realized by a controlled system, as well as by a control apparatus operating with analog circuitry.

Abstract: A fuel cut-off control can prolong a period of time in which the engine speed is maintained at a range suitable for performing fuel cut-off and shorten a period of time in which the engine speed is in a fuel recovery range to minimize fuel consumption during engine deceleration. In a fuel cut-off control system in a fuel injection internal combustion engine with an automatic transmission, the fuel cut-off control system is responsive to a brake switch signal and an engine speed signal having a value above a fuel recovery threshold to decrease the value of a fuel cut-off threshold to again perform the fuel cut-off even in the normal fuel recovery range. Down shifting of a transmission gear is performed to increase engine speed to a level beyond the fuel cut-off threshold to prolong the fuel cut-off period.

Abstract: A fuel injection device of a diesel engine which stops fuel injection and throttles intake air during engine braking so that engine vibration, noise, harmful exhaust gas, and fuel consumption are all reduced. The device includes an intake valve interlocked with an accelerator to throttle intake air during accelerator nonoperation, sensors for detecting an engine braking condition, and a computer for controlling fuel injection in response to signals from engine sensors.

Abstract: A fuel cut-supply control system for a multiple-cylinder internal combustion engine which can effectively prevent engine vibration or shock generated when fuel is cut off or resupplied. The cylinders of the engine are divided into two cylinder groups and fuel is cut off or resupplied to one cylinder group a predetermined delay time after fuel has been cut off from or resupplied to the other cylinder group. The delay time is so determined that vibration caused by the first cylinder group is 180 degrees out of phase with that caused by the second cylinder group. The control system according to the present invention comprises a delay circuit and a first and second fuel cut-supply control sections, in addition to the conventional fuel cut-supply control system.

Abstract: A control device for a supercharged internal combustion engine is proposed, in which a device for fuel limitation during overrunning is also used for limiting the fuel metering in a definite manner in the event that a threshold value of the charge pressure is exceeded. To this end, a switch actuated by the charge pressure is connected parallel to a switch triggered during overrunning. In the event that the threshold value of the charge pressure is exceeded, overrunning is simulated accordingly, and the associated provisions for fuel limitation for such an event are initiated.

Abstract: A method of controlling the fuel supply to an internal combustion engine immediately after termination of a fuel cut operation thereof which is effected at deceleration of the engine, in a manner increasing the quantity of fuel being supplied to the engine by an increment which is set in sychronism with generation of pulses of a predetermined control signal generated at predetermined crank angle positions of the engine. The magnitude of change of the rotational speed of the engine is detected for a period of time after a transition of the operative state of the engine from the fuel cut operation to a normal operation wherein fuel supply is effected has been detected and before a predetermined number of pulses of the above predetermined control signal are generated.

Abstract: A vehicle including an internal combustion engine having a fuel supply system for providing a supply of fuel, a deceleration detecting device for detecting that the engine is in deceleration, a heater having heat exchanger for bringing air in the vehicle into a heat exchange relationship with engine cooling medium so that the air in the vehicle is heated by the engine cooling medium, a heater operation detecting device for detecting that the heater is in operation, a fuel supply control device responsive to outputs of the deceleration detecting device and the heater operation detecting device for interrupting the supply of fuel when the engine is in deceleration and the heater is not in operation.

Abstract: Apparatus to control throttle valve position during deceleration of an engine which includes a first stopper for stopping closing movement of the throttle valve at the idling position, a mechanism for removing the first stopper from operation at the time of deceleration, and a second stopper for stopping movement of the throttle valve at a closed-valve position which is beyond the idling position in the closing direction. The mechanism for removing includes a delay mechanism for delaying the foregoing removal of the first stopper at the time of deceleration.

Abstract: A method for controlling the quantity of fuel being supplied to an internal combustion engine having a power transmission means for transmitting engine torque to vehicle wheels. The fuel quantity is controlled to required values after termination of a fuel cut operation which is effected at deceleration of the engine, by the use of increments set in synchronism with generation of pulses of a predetermined control signal. The state of engagement of the power transmission means is detected for a period of time after a transition of the operative state of the engine from the fuel cut operation to a normal operation wherein fuel supply is effected has been detected and before a predetermined number of pulses of the above predetermined control signal are generated.

Abstract: In an internal combustion engine mounted on a four wheel drive (4WD) vehicle, the fuel cut-off engine speed (N.sub.c) and the fuel cut-off recovery engine speed (N.sub.R) are calculated in accordance with the coolant temperature of the engine. When the vehicle is in a 4WD mode, predetermined minimum values are set in the calculated fuel cut-off engine speed and the calculated fuel cut-off engine speed. When the throttle valve is completely closed and it is determined that the current engine speed is higher than the calculated fuel cut-off engine speed (N.sub.c) or the calculated fuel cut-off recovery engine speed (N.sub.R), which is selected in accordance with whether or not the fuel cut-off operation was being carried out, the fuel cut-off operation is carried out.

Abstract: A deceleration control device is applied to an internal combustion engine having an air intake passage and a throttle valve disposed in the air intake passage. The device includes a fuel supply cut-off valve and a vacuum control valve. The cut-off valve selectively interrupts and recommences supply of fuel to the engine. The control valve conducts air to the air intake passage downstream of the throttle valve to weaken the vacuum in the air intake passage downstream of the throttle valve and suspends the conduction of the air. The device also includes a mechanism for causing the control valve to suspend the conduction of the air when the cut-off valve recommences supply of fuel.

Abstract: A method of controlling the fuel supply to an internal combustion engine at deceleration thereof, wherein the fuel supply to the engine is interrupted when the engine is operating in a predetermined operating region in which is satisfied at least a condition that the intake passage pressure is lower than a predetermined value, while the engine is decelerating. The predetermined value of intake passage pressure is corrected in a manner responsive to a detected value of atmospheric pressure encompassing the engine. Preferably, the intake passage pressure is detected in terms of absolute pressure at a zone downstream of a throttle valve arranged therein, and the above predetermined value of intake passage pressure is corrected to smaller values as the detected value of the atmospheric pressure decreases.

Abstract: A current regulator is proposed for use in an electronically controlled, continuously operating gasoline injection system, with the aid of which a control element can be supplied with different current values depending upon the operating states of the engine. In addition to a current regulating phase during active operation, it is possible with the proposed current regulator to reverse the direction of current flow in the control element for the sake of blocking the supply of fuel during overrunning. Towards this end a circuit apparatus links signals relating to rpm, throttle valve position and temperature. Furthermore two safety circuit arrangements are proposed for the current regulator, so that in case of a failure of important components there is no impairment of safety, and emergency operation is assured.

Abstract: A fuel supply control method for controlling the fuel supply to an internal combustion engine at deceleration, wherein the fuel supply to the engine is interrupted when the engine is operating in a predetermined operating region while it is decelerating. The fuel supply is interrupted when the engine is operating in either of the following operating conditions: (1) when the throttle valve is in a substantially fully closed position while the engine is decelerating; and (2) when the throttle valve is in a position other than the substantially fully closed position and simultaneously the engine is operating in a predetermined operating region determined by the engine rotational speed and another engine operation parameter relating to the intake air quantity of the engine, preferably, the intake passage pressure.

Abstract: An engine is coupled to an automatic power transmission having a lockup device. The lockup device is in an operative position when the speed of the engine is higher than a preset lockup reference level, and is in a rest position when the engine speed is not higher than the lockup reference level. A deceleration sensor detects when the engine is required to decelerate. A speed sensor detects the speed of the engine. A fuel-control device is associated with the deceleration sensor and the speed sensor to supply fuel to the engine when the engine is required to decelerate and the engine speed is lower than an adjustable fuel-supply control level. The fuel-control device also serves to interrupt the supply of fuel to the engine when the engine is required to decelerate and the engine speed is not lower than the fuel-supply control level. When the lockup device is in the rest position, the fuel-supply control level is equal to a first preset value.

Abstract: A throttle valve control apparatus having a valve closing device for closing the throttle valve beyond the idling position thereof. The valve closing device is controlled by a control mechanism which is responsive to engine speed and includes an engine speed sensor. The closing device is operated at the time of deceleration of the engine from the condition that the engine speed is above a predetermined minimum ON speed and is released from operation when the engine speed is lowered to a predetermined OFF speed which is near the idling speed. The ON speed is set to be above an upper-limit of an adjustment error range predetermined about the actual idling speed.

Abstract: An electronic control type fuel injection system in which, at the time of engine deceleration the fuel injection is stopped, and when resuming to a normal fuel injection from the fuel injection stopped condition, if the reducing rate of the engine speed is smaller than a preset value, a smaller amount of fuel than the amount of fuel injection during normal operation as if fuel injection had not been stopped is first injected and subsequently the amount of fuel to be injected is gradually increased, while when the reducing rate of the engine speed is larger than the preset value, a larger amount of fuel than the fuel injection amount during normal operation is injected.

Abstract: The speed (54, 56) of the free turbine (40) of a helicopter engine (20) is compared (103) with the speed (105, 106) of the helicopter rotor (10) to indicate (101, 102) autorotation, and the deceleration (108) of the rotor above a threshold magnitude (110) is utilized (81, 68, 69) to increase fuel flow (72) to the engine in anticipation of rotor speed droop which would otherwise occur during recovery from the autorotation maneuver.

Abstract: Throttle valve control apparatus including an idle-speed increasing device for causing the throttle valve to open beyond the normal idle position according to engine load, a valve closing device for permitting the throttle valve to close beyond the normal idle position when the engine is decelerating or the like, and a restraining mechanism for restraining the operation of the idle-speed increasing device during operation of the valve closing device.

Abstract: A carburetor comprises: a main barrel; a throttle situated in the barrel; an idle system which, from a cavity full of fuel, opens into the main barrel through progression and idle mixture holes; the idle system comprises elements for metering fuel and air, which form a primary emulsion. There are several suitably sized passages in the idle system through which the fuel or emulsion flow; the following cooperate with the said passages: first elements for excluding the flow from some of the said passages, keeping at least one open to prevent the idle system from emptying during accelerator release; second organs for positioning the said first elements; third devices for recognizing accelerator release and checking the said second organs.

Abstract: A fuel supply control method for controlling the fuel supply to an internal combustion engine at deceleration, wherein the valve opening of a throttle valve of the engine is detected while the throttle valve is being closed and each time each pulse of a predetermined sampling signal is generated, a variation in the same valve opening occurring between adjacent pulses of the sampling signal is determined as a control parameter value, and the fuel supply to the engine is interrupted in dependence upon the control parameter value.