Abstract: A two cycle internal combustion engine is provided with a fuel system including a low pressure fuel pump (204) and solenoid valve (206) supplying and metering fuel to the engine crankcase through a fuel line, without a carburetor, without a high pressure fuel pump, without high pressure fuel injectors, and without a constant fuel pressure regulator. The system senses the amount of combustion air supplied to the engine, and senses fuel flow velocity using a restriction orifice in the fuel line producing a fuel pressure drop indicating fuel flow velocity. A conduit is connected between the crankcase at a transfer passage and the fuel line downstream of the restriction orifice and passes warm presurized air-fuel mixture from the crankcase through the transfer passage to the fuel line to improve fuel atomization.

Abstract: A method and apparatus for controlling the idle circuit of a carbureted engine is disclosed. The apparatus includes a solenoid valve for blocking the idle circuit of a carburetor when engine speed exceeds a preset limit. Electronic circuits are disclosed to respond to engine speed and to activate the solenoid valve. The method disclosed involves interrupting the carburetor's idle circuit when engine speed exceeds a preset limit. In this fashion, fuel is conserved and air pollution is reduced.

Abstract: A diagnostic system of an air-fuel ratio control device including an O.sub.2 sensor and an air bleed control valve actuated in response to a signal output by the O.sub.2 sensor. When the electric control current fed into the air bleed control valve reaches an upper limit or lower limit and remains at the upper limit or lower limit for a fixed time, the diagnostic system determines that the air-fuel ratio control device has malfunctioned. When the temperature of the engine cooling water is high, a diagnosis is prohibited, to prevent an incorrect diagnosis.

Abstract: A carburetor arrangement changes the ratio of air and fuel in the air/fuel mixture for an internal combustion engine of a handheld motor-driven apparatus such as a chain saw, hedge trimmer or the like. The carburetor arrangement includes a membrane carburetor with a regulating membrane by means of which a valve needle is lifted from a valve seat against the force of a spring. The valve needle and valve seat conjointly define a valve for admitting fuel into a chamber of the carburetor. A positioning member is mounted with respect to the regulating membrane and is actuable in dependence upon the rotational speed of the engine. The actuation occurs such that the valve needle is additionally displaced a further incremental amount in response to a predetermined rotational speed of the engine thereby enriching the air/fuel mixture by an additional amount.

Abstract: An engine apparatus comprising an internal combustion engine operable throughout a range of speeds including a minimum speed, a maximum speed, a first speed between the minimum speed and the maximum speed, and a second speed between the first speed and the maximum speed, the engine including an intake zone wherein relatively low pressure is created in response to engine operation, a primary fuel delivery system for delivering fuel from a fuel source to the engine for normal engine operation, a selectively actuatable secondary fuel delivery system for delivering enrichment fuel from a fuel source to the engine, and an electrical control circuit for selectively actuating the secondary fuel delivery system only when the pressure in the zone is below a predetermined level and the speed of the engine is above the first speed and below the second speed.

Abstract: A carburetor for internal combustion engines has an automatic starting device comprising a choke valve based toward opening by the air flow and toward closure by a temperature responsive bimetallic spiral when cold. A device further comprises a stop member an electrically controlled movable stop member having at least one active position in which it permits complete closure of the choke valve and a rest position in which it prevents closing movement of the choke valve beyond a predetermined position, and means arranged to bring said stop member into said active position, responsive to closure of the ignition switch and for being inhibited if after a sequence of operation of the cold engine during a period greater than a first threshold value, then rest condition of the engine for a period less than a second predetermined value.

Abstract: A fuel supply system of a type for use with an internal combustion engine employs a valve assembly and a circuit for controlling the valve assembly to supply fuel to the engine at a greater or lesser rate respectively in response either to initial closure of an ignition switch when the engine is cold, according to one mode of operation, and in response to acceleration of the engine, according to another mode of operation. The fuel supply system serves to include means for preheating or vaporizing the fuel supplied to the engine.

Abstract: A feedback fuel metering control system is provided for an internal combustion engine and eliminates the need for high pressure fuel injectors, a high pressure fuel pump and a constant fuel pressure regulator. The system senses the amount of combustion air supplied to the engine, senses fuel flow velocity, and controls the amount of fuel supplied according to the amount of combustion air the fuel flow velocity.

Abstract: An automatic choke system has a thermostatic spring connected to a choke valve, and a heater for heating the thermostatic spring so as to open the choke valve. A control circuit is provided for controlling the current passing through the heater. At starting of an engine, when cooling water temperature is lower than a predetermined temperature the control circuit operates to decrease the current so as to slowly open the choke valve. When the cooling water temperature is higher than a predetermined temperature, a rated current is supplied to the heater so as to quickly open the choke valve.

Abstract: An airstream driven rotor assembly with a centrifugal pump forcing a measured fuel quantity through a fixed orifice in direct substantially linear proportion to rotor speed and thus to airstream volume. The ultimate fuel-air ratio is corrected for optimum operation by slightly changing, in response to measured parameters, one of the mixture constituents. In one embodiment, the fuel discharge bore (9) of a rotor (7) is dimensioned that the rotor carburetor (2) produces a lean mixture with a .lambda.-value which is constant for all operating points approximately 1.25. For fuel-air ratio correction additional fuel is brought into atomization ring (11) of rotor (7), by which the fuel-air ratio in the lean mixture is changed and at the engine operating points the .lambda.-values are adjusted to give most favorable fuel consumption, output and pollution.

Abstract: In order to insure that, even when there arises a change in the rate of air flowing through an intake mixture passageway, the air-fuel ratio of the mixture which is to be supplied to an engine is always kept constant, the fuel control system comprises: an intake mixture passageway having a first negative pressure generating section and a second negative pressure generating section provided upstream of the first negative pressure generating section for generating a negative pressure weaker than that in the first negative pressure generating section; a fuel passageway having its one end opening in the first negative pressure generating section and its other end connected to a float chamber via a fuel metering jet; an electromagnetic valve for controlling the rate of the fuel flowing through the fuel passageway; a negative pressure passageway having its one end opening in the second negative pressure generating section and having its other end connected to the fuel passageway at a site located between the fuel m

Abstract: An electronic air-fuel mixture control system is adapted to an internal combustion engine to determine an optimum air-fuel ratio in dependence upon renewal of plural learning values related to a plurality of load regions of the engine. The control system is arranged to select one of the learning values in accordance with the engine load and to prohibit learning of the selected learning value when a difference between the selected learning value and the adjacent learning value is more than an allowable value determined in consideration with allowable fluctuation of the air-fuel ratio caused by change of the amount of air flowing into the engine.

Abstract: In a carburetor having a flow control element axially movable within an air bleed passage in the carburetor body for controlling the cross-sectional area of the passage and a stepper motor on the body for effecting axial movement of the control element, an input circuit produces an electric signal indicative of the operating condition of an engine. A computer determines rotary steps of the motor in response to the electric signal for optimizing the cross-sectional area of the passage in relation to the operating condition of the engine, an a whether the number of the determined rotary steps is more than the actual rotary steps of the motor. A first command signal and a second command signal, and first and second control signals are produced respectively for effecting one rotary step of the motor in a direction defined by each of the command signals.

Abstract: A device for increasing an amount of fuel to be supplied to an engine includes a fuel increasing mechanism for supplying an added amount of fuel to the engine, and an electric control circuit including a low-temperature sensor for detecting a low temperature of the engine to produce a first signal capable of actuating the fuel increasing mechanism, and a neutral-gear-condition detector for detecting the neutral-gear-condition of a gear transmission associated with the engine to produce a second signal. The fuel increasing mechanism is inactivated in response to the second signal from the neutral-gear-condition sensor by overriding the low-temperature sensor to prevent the increase of fuel while the gear transmission is in neutral. A second embodiment employs additional sensors for air temperature, engine r.p.m., vehicle speed and the park-condition of an automatic transmission also for controlling the fuel increase.

Abstract: A starting system of an engine according to the present invention comprises an electromagnetically-operated fuel resupply pump for supplying auxiliary fuel to an intake passage of the engine, and various detectors for detecting the operating conditions of the engine, e.g., engine speed, temperature of engine cooling water, drive of a starting motor, etc., and a control circuit for controlling the drive of the fuel resupply pump in accordance with signals from the detectors. The control circuit is partially formed of a microcomputer, which controls the pump so that a pulse voltage is applied to a solenoid of the pump for a longer time when the engine is in a cranking state than when the engine is in any other operating state.

Abstract: An air-fuel ratio control system for an internal combustion engine has an electromagnetic valve for correcting the air-fuel ratio of air-fuel mixture, an O.sub.2 sensor for detecting oxygen concentration in exhaust gases, and a feedback control circuit including a pulse generating circuit for generating pulses, the duty ratio of which is dependent on the oxygen concentration. The system has an engine deceleration detecting circuit and a light load detecting circuit for producing a deciding signal. Pulses having a fixed duty ratio are applied to the electromagnetic valve in response to the deciding signal so as to enrich the air-fuel mixture at the deceleration when the throttle valve closes.

Abstract: A carburetor is provided with an automatic starting device, more especially for motor car engines, comprising a butterfly valve controlled by the driver and -for starting up and cold running of the engine- an automatic starting device. This device comprises a start air valve (choke) and a wax capsule which controls the position of the air valve and the minimum opening position of the butterfly valve. The wax capsule is provided with a heating resistor and a temperature sensor. The starting device further comprises a computer having inputs connected to the temperature sensor and to sensors supplyng signals representative of the operating conditions of the engine. It controls the electric power applied to the heating resistor. The computer imposes on the butterfly valve and on the air valve a degree of opening which depends, on the one hand, on the temperature sensitive element during start up of the engine and, on the other hand, on the number of revolutions effected by this latter from start up.

Abstract: An air-fuel ratio control system for an internal combustion engine has an electromagnetic valve for correcting the air-fuel ratio of air-fuel mixture, and an O.sub.2 sensor for detecting oxygen concentration in exhaust gases. An engine coolant temperature sensor is provided for producing an engine temperature signal when the temperature is higher than a predetermined value, and an O.sub.2 sensor condition detecting circuit is provided for producing a non-activation signal when the O.sub.2 sensor is not activated. Engine restart operation is detected by the engine temperature signal and non-activation signal. When the restarting of the engine detected, pulses with a duty ratio of which is dependent on the coolant temperature are applied to the electromagnetic valve, so as to prevent extreme enrichment of the air-fuel mixture.

Abstract: An air-fuel ratio control system for an internal combustion engine has an electromagnetic valve for correcting the air-fuel ratio of air-fuel mixture, and an O.sub.2 sensor for detecting oxygen concentration in exhaust gases. A detecting circuit is provided for producing an acceleration signal when the engine is accelerated at cold engine operation. A pulse generating circuit is provided for producing a plurality of pulses, the duty ratios of which are proper for air-fuel ratio at acceleration in cold engine operation. A changeover switch is provided to respond to the acceleration signal for applying the pulses to the electromagnetic valve so as to control the air-fuel ratio.

Abstract: An air-fuel ratio control system for an internal combustion engine has an electromagnetic valve for correcting the air-fuel ratio of air-fuel mixture, an O.sub.2 sensor for detecting oxygen concentration in exhaust gases, and a feedback control circuit including a PI circuit, and a pulse generating circuit responsive to the output of the PI circuit for generating pulses, the duty ratio of which is dependent on the output of the PI circuit. A steady state detecting circuit is provided for producing a steady state signal when the magnitude of acceleration of the engine is within a predetermined range. The constant of the PI circuit is decreased by the steady state signal for preventing overshooting of the air-fuel ratio control.

Abstract: An air intake side secondary air supply system for an internal combustion engine having an air intake system using a carburetor and an air intake side secondary air supply passage leading to the downstream of the carburetor, and equipped with a fuel increment control system. The system includes an oxygen concentration sensor producing an output signal whose level is substantially proportional to an oxygen concentration of the exhaust gas, and an open/close valve disposed in the air intake side secondary air supply passage controlled in accordance the output signal of the oxygen concentration sensor. The system is adapted close the open/close valve continously to stop the air/fuel ratio control when an operation of the fuel increment control system is detected.

Abstract: A warming-up system of an engine for an automobile according to the present invention is provided with main and auxiliary nozzles in an air intake passage of a carburetor. The auxiliary nozzle is connected to an electromagnetically-operated fuel resupply pump. The warming-up system is further provided with a position detector for determining whether or not a throttle valve is in an open position, a rotation detector for detecting the rotational frequency of the engine, and a control circuit for controlling the drive of the pump in accordance with signals from the detectors. Based on the rotational frequency of the engine detected by the rotation detector, the control circuit determines whether the engine is in a cranking state or in a complete detonation state. When the engine is in the complete detonation state, the control circuit drives the pump to supply a predetermined quantity of auxiliary fuel to the intake passage through the auxiliary nozzle.

Abstract: Carbureting device for supplying in air-fuel mixture to at least one heat engine combustion chamber and of the type comprising a passage of rich mixture and a passage of additional air wherein an element for controlling the constriction section of the passage of additional air is coupled to an actuating motor dependent upon the speed of rotation of the heat engine, this device being applied to a carburetor in order to suppress the enrichment pump and to obtain a lean air-fuel mixture for high rotation speeds of the engine.

Abstract: An air-fuel ratio control system for an internal combustion engine has an electromagnetic valve for correcting the air-fuel ratio of air-fuel mixture, an O.sub.2 sensor for detecting oxygen concentration in exhaust gases, and a feedback control circuit including a PI circuit for producing a PI value, and a pulse generating circuit responsive to the PI value for generating pulses duty ratio of which is dependent on the PI value. The PI value is corrected to a PI value operative to rapidly changing the duty ratio of the pulses so as to enrich the air-fuel mixture, ar rapid deceleration of the engine.

Abstract: A method for controlling the quatity of fuel being supplied to an internal combustion engine, immediately after termination of a fuel cut operation which is carried out when the engine is operating in a predetermined operating region while it is decelerating. The fuel quantity is controlled to a required value after termination of a fuel cut operation, by increasing a quantity of fuel set at least as a function of intake pipe pressure by an increment which is set in synchronism with generation of pulses of a predetermined control signal. The increase of the fuel quantity is effected 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 control signal are generated, so long as the magnitude of a variation or change in the rotational speed of the engine is determined to be larger than a predetermined value.

Abstract: A motor vehicle fuel system operable selectively to supply metered quantities of petrol or LPG in its gaseous state to a carburetter induction passage. The LPG system includes a single stage pressure regulator and an injection valve which may be a digital or an analogue valve. The regulator operates to vary the pressure of gaseous LPG with variations in engine loading by referring that pressure across a single diaphragm to the pressure established in the induction passage downstream of the throttle valve by operation of the engine, while maintaining that regulated gas pressure above that subsisting in the induction passage upstream of the throttle valve.

Abstract: An air-fuel ratio control system for an internal combustion engine having an oxygen concentration sensor for a feedback control of air-fuel ratio, including an intake air temperature sensing means and a control means for operating/stopping the feedback control of air-fuel ratio in accordance with the detected value of the intake air temperature. When the intake air temperature is below a predetermined level, the feedback control is stopped, and an auxiliary fuel supply means is activated, and at the same time a supply of atmospheric air into a slow speed fuel supply system of the engine is stopped. Thus, the air-fuel ratio is controlled to the rich side when the open loop control is selected, in order to secure a stable engine operation.

Abstract: A first temperature sensor senses the temperature of intake air supplied to an internal combustion engine before the intake air is mixed with fuel supplied thereto. A second temperature sensor senses the temperature of the mixture of the intake air and fuel within the intake air passage. A control unit controls the fuel injection quantity in accordance with the difference between the sensed temperatures, thereby causing the actual air-fuel ratio to coincide with a desired air-fuel ratio. The desired air-fuel ratio is adjusted in accordance with the throttling effect of a throttle valve in the intake air passage and with engine speed.

Abstract: An increase in the amount of fuel when an engine is started or being idled is controlled on the basis of a detected intake air temperature or outside air temperature in addition to detected engine speed, intake air pressure and engine coolant temperature. Therefore, it is possible to obtain a mixture with an appropriate air-to-fuel ratio corresponding to intake air temperature in starting the engine, thus improving engine starting characteristics at low outside air temperature.

Abstract: A double carburetor including a primary suction conduit and a secondary suction conduit located in a suction passage of an internal combustion engine equipped with a turbosupercharger for supplying supercharged air to a combustion chamber by means of a compressor driven by a turbine rotated by the energy of exhausts has an air-fuel ratio correcting control valve for a primary main fuel system of the primary suction conduit and another air-fuel ratio correcting control valve for a secondary main fuel system of the secondary suction conduit. The carburetor also has a drive unit which is operative, when the turbosupercharger is put into action, to actuate the air-fuel ratio correcting control valves for the primary and secondary main fuel systems to correct the air-fuel ratio of fuel-air mixtures supplied to the engine by increasing fuel flow or decreasing air flow therethrough.

Abstract: A carburetor is provided which has a main barrel in which there is a throttle which turns integrally with a shaft. An idle system opens into the main barrel through three holes; and a lever is splined to the shaft and connected to the accelerator to open the throttle against the action of a spring. Stop devices operate on the lever to define a first position of the throttle for which the holes are upstream. A second lever is idle mounted on the shaft. This second lever uses pushers and operates against the action of a rod positioned by a rotating cam with an electromagnetic element, or electronic gear box to rotate the first lever. This second lever defines, when the accelerator is released, small opening positions of the throttle differing from the first position. A microprocessor gearbox processes the signals expressing the functioning conditions of the engine to operate the electromagnetic element or electronic gear box.

Abstract: The invention relates to a fuel metering and distribution system for an internal combustion engine comprising an open fuel reservoir 18 into which fuel is metered and a set of capillary tubes 20 each extending from the fuel reservoir 18 to a point in an induction manifold adjacent the intake valve of a respective one of the engine cylinders. The fuel may either be metered by a carburettor-like arrangement drawing fuel from a float chamber or by means of a single solenoid valve connected between the reservoir and a source of fuel under pressure. The ends of the fine tubes terminate in the fuel reservoir immediately above the fuel level, whereby as the fuel rises, the additional fuel metered into the reservoir is sucked into the fine tubes and transferred directly to the engine cylinders.

Abstract: A fuel supply control system for a vehicle engine carburetor and particularly a carburetor that includes a variable venturi portion and fixed venturi or nozzle portion. The system includes a fuel valve for supplying additional fuel to the nozzle under low speed or high load conditions sensed by elements responsive to those conditions. The system also includes an air valve for controlling the air supplied to the nozzle and a sensor for closing the air valve to thereby also increase the fuel supplied to the nozzle under high load conditions. Other sensors of engine temperature also control the operation of the fuel and air valves.

Abstract: A vehicle has a combustion engine, ground-engaging drive wheels, a power transmission for conveying power from the engine to the wheels, an induction passage for supplying motive fluid to the engine, a source of fuel, adaptive structure defining a fuel metering system communicating generally between the source of fuel and the induction passage, the adaptive structure having a valving arrangement in the fuel metering system effective to controllably alter the rate of metered fuel flow through the fuel metering system, and a manually controlled adjustment operatively connected to the valving arrangement, the manually controlled adjustment being effective to selectively control the valving arrangement in order to thereby selectively alter the rate of metered fuel flow to the engine.

Abstract: A fuel supply control system for an internal combustion engine has first and second step motor drivers for driving a step motor operatively coupled to a fuel supply control means such as a throttle valve. An initial step position setting memory stores an initial preset step position of the step motor, and a target step memory stores a target step position of the step motor dependent on an accelerator pedal position. A driver selector selects the first step motor driver for driving the step motor to the initial preset step position in response to a signal from a power-on detector, and selects the second step motor driver for driving the step motor to the target step position in response to a signal from an engine self-operation detector.

Abstract: An air/fuel ratio control method in which the air/fuel ratio of an air/fuel mixture being supplied to an internal combustion engine is controlled to required values by the use of a first coefficient which has a value variable with a change in the output of the oxygen concentration detecting means, during feedback mode control, and by the use of a second coefficient which is a mean value of values of the first coefficient applied during the above feedback mode control, during operation of the engine in a mode other than the feedback mode control. When the above second coefficient has a value falling outside a predetermined range of values, the value of the same coefficient is set to a predetermined value. Preferably, the above predetermined value of the second coefficient is set at a constant value of 1.0 or a constant value adapted to obtain a required quantity of the air/fuel ratio of an air/fuel mixture to the engine in dependence upon the operating characteristics of the engine.

Abstract: A method of controlling the duty ratio of operation of a solenoid control valve in a fluid passage to control the flow rate of fluid in the fluid passage to a desired value. A flow rate value range is divided into a plurality of flow rate value regions between first and second extreme flow rate values which the fluid can assume when the duty ratio assumes corresponding minimum and maximum values. A first predetermined duty ratio value is preset corresponding to each of the divided regions and dependent upon the magnitude of manufacturing variations of the duty ratio-to-flow characteristic of the valve. A second larger predetermined duty ratio value is preset corresponding to each of the divided regions.

Abstract: A control system for a feedback carburetor in which a controlled vacuum is applied to the carburetor fuel bowl to reduce the fuel flow rate and provide maximum fuel economy. Engine speed is monitored and reduced a predetermined amount during steady state cruising through use of an air control solenoid to apply the controlled vacuum. The controlled vacuum is removed during acceleration or when engine speed is outside the range of steady state cruise speed.

Abstract: An apparatus is disclosed for controlling an opening angle or a position of a throttle valve on complete firing in an internal combustion engine until the said engine has shifted to a situation of warm-up after the said engine started and the complete firing thereof was sensed. The control apparatus is so constructed that the throttle valve is closed at high speed to a predetermined opening angle which has an intermediate value between a starting position and a warming-up position when complete firing of the engine is sensed, and thereafter the throttle valve is driven to close until it reaches the warming-up position at a relatively low speed.

Abstract: A carburetor is provided which includes a sensor mounted in the engine head for monitoring cooling water temperature, and sensors for monitoring engine RPM and intake manifold absolute pressure. A first positioning unit positions the throttle valve, prior to depression of the accelerator, in a plurality of angular positions as a function of the cooling water temperature. A second positioning unit positions the choke valve as a function of the cooling water temperature to limit the amount of opening of the choke valve caused by air sucked into the carburetor by the engine. The second positioning unit has a spring for biasing the choke valve to close the choke valve to prevent swinging of the choke valve when the engine is turned off. A central processing unit receives signals from the first, second and third sensors to control the first and second positioning units to position the throttle valve and the choke valve respectively.

Abstract: A fuel metering apparatus is shown as having a throttle body with an induction passage therethrough and a throttle valve for controlling flow through the induction passage, a fuel-air mixture discharge member is situated generally in the induction passage downstream of the throttle valve, an air passage communicates between a source of air and the fuel-air mixture discharge member, the air passage is shown as also including a flow restrictor therein which provides for sonic flow therethrough, and a fuel metering valving assembly having a ball valve member is effective for metering liquid fuel as at a superatmospheric pressure and delivering such metered liquid fuel as into the air passage upstream of the flow restrictor thereby causing the thusly metered liquid fuel and air to pass through the sonic flow restrictor before being discharged into the induction passage by the fuel-air mixture discharge member, the ball valve member at least partly receives at least one resilient member which urges the ball valve

Abstract: A fuel metering apparatus is shown as having a throttle body with an induction passage therethrough and a throttle valve for controlling flow of induction air through the induction passage, first and second passages are provided with the first passage having an inlet at one end and communicating at its other end with a source of fuel, the second passage has an inlet at one end and communicates with the flow of induction air thereby serving as a metered fuel discharge nozzle, fuel at a regulated superatmospheric pressure is delivered as through a movable tubular member and discharged through an open end thereof in a manner whereby such discharged fuel is alternately directed toward the inlet of the first passage and toward the inlet of the second passage, a magnetic field is cyclically produced as to thereby cause movement of the movable tubular member as to thereby cause such discharged fuel to be alternately directed to the inlets of the first and second passages, the portion of the fuel directed to the inle

Abstract: A mixture control apparatus for a carburetor which precludes otherwise possible occurrence of fluctuation in the opening angle of the throttle valve even when the engine operation happens to fall near the boundary between the cold state and the hot state. The electric motor for driving the throttle valve is prevented from moving to the side of reverse rotation thereof from the side of normal rotation thereof past a home position after said engine has been changed to its hot state and unless a stop of said engine is detected.

Abstract: A carburetor is described, comprising a main barrel; a throttle; an idle system positioned between a cavity full of fuel and the main barrel, with progression and idle mixture holes, the opening of which is regulated by the conical point of an element to be positioned in a first position with respect to the said idle mixture hole by means of screws; the system comprises a hole for metering the fuel and a bush for metering the emulsion air; a first electromagnetic element has an obturator for closing the said hole with a ball; the element is connected to the movable keeper of a second electromagnetic device for moving the conical point away from the idle mixture hole; control devices are present to operate the said electromagnetic devices during accelerator release.

Abstract: An air fuel ratio control system includes a correction system for correcting air/fuel ratio depending on measured atmospheric air pressure. The correction system has sensors for detecting engine operating conditions. A reference intake manifold pressure corresponding to the detected engine operating condition at sea level is obtained from the engine operating condition. The reference atmospheric air pressure is compared with the measure intake manifold absolute pressure to determine a difference value. Based on the difference, a correction value for controlling the air/fuel ratio is determined.

Abstract: An air-fuel ratio compensating apparatus for the carburetor of an internal combustion engine has first and second valves having equal control (input) current-opening characteristics and provided in main and slow system air bleed paths respectively to control sectional area of flow in the main and slow system air bleed paths in relation to the output of an air-fuel ratio sensor, electronic control circuit which sends the control current to the first and second valves in such a way that the opening of the second valve is always larger than that of the first valve. Thus, flow of the main system air bleed is restrained during the initial part of the acceleration period so as to reduce the amount of noxious component in the exhaust gas.

Abstract: An air-fuel ratio control system for an internal combustion engine for controlling the air-fuel mixing ratio of a combustible mixture to be supplied to the engine on a feedback control scheme in dependence on the concentration of a constituent of exhaust gases which is a function of the air-fuel mixing ratio of the combustible mixture having been combusted. The feedback control scheme of the air-fuel ratio control system for adjusting the ratio to the stoichiometric value is temporarily disconnected to permit the mixture to be enriched so that the engine can produce a relatively high power output during the high load engine operating condition.

Abstract: A method and apparatus for optimizing operational variables of an internal combustion engine, such as the output, or the fuel consumption, by means of the variation of engine variables and the detection of the relative variations thus resulting in the operational variables and a corresponding follow-up of the engine variables which includes a control device, with which the engine variables are preset and are variable at selectable times and/or upon the appearance of certain operational variables or changes in operational variables and the corresponding reactions serve for determining the optimum output and/or the minimum specific fuel consumption. Thus, on the basis of the most precise possible presetting of the various values, a change in the engine variables and a corresponding change in the individual variables in accordance with the particular reaction at that time take place only at fixed times or at fixed combinations of operational variables.

Abstract: An apparatus for enriching an air-fuel mixture supplied by a carburetor upon starting operation of an internal combustion engine comprises a fuel quantity increasing passage which is operative independent of main fuel supply system. The passage has an inlet communicated to a fuel supply source and an outlet opened at a location downstream of a throttle valve. The amount of fuel ejected from the outlet of the passage is controlled by a control signal which represents a product of a value variable in dependence on a suction vacuum, the rotational frequency of the engine and a value variable in dependence on the temperature of engine cooling water.

Abstract: An engine control method generally applicable to those control systems of the engine such as an ignition system, fuel injection system, etc., which are controlled to optimum operation in accordance with the engine operating conditions. In this method, an operation starting timing and an operation ending timing of the control system, e.g., in the case of the ignition system, an ignition coil energization starting timing and an ignition timing (an energization ending timing) are computed at each of predetermined computing cycles, and the latest computed ignition timing, for example, which is computed after the coil energization has been started further taking into consideration of the actual coil energization timing and a minimum required energization period is compared with an ignition timing computed in the preceding computing cycle, and a corrective computation of the latest computed ignition timing is carried out depending on the result of the comparison to obtain an optimum ignition timing.