Abstract: Engine parameters are detected to set a basic ignition timing, and this basic ignition timing is forcibly changed to effect feedback control in which engine output is detected for finding an optimum combination of ignition timings of the individual cylinders. Engine is operated with a plurality of different ignition timing combinations, where the number of the combinations equals the number of the cylinders added by one. The engine is further operated with one of the ignition timing combinations so that the engine is operated twice with an identical ignition timing combination. As a result engine output change caused by factors other than ignition timing change is detected. Thus, one of a plurality of ignition timing combinations, which gives the lowest engine speed is found and is replaced with a new ignition timing combination with which the engine produces higher output. The replacement is carried out selectively in accordance with the variation rate of the engine output data.

Abstract: A device for correcting the air/fuel ratio of a mixture being supplied to an internal combustion engine, by the use of a correction coefficient which has its value determined as a function of intake air temperature in the intake pipe of the engine, by a predetermined equation. Further, the air/fuel ratio may be corrected by the use of a second correction coefficient which has its value increasing as the intake air temperature decreases from a predetermined value. The above two correction coefficients have their values determined by means of arithmetic calculation, or by means of selective reading from a plurality of predetermined values stored in their respective memories, both based upon a detected value of the intake air temperature.

Abstract: In a closed loop control system for air/fuel ratio control of an internal combustion engine, an integration correction factor is derived from the output signal of a gas sensor indicative of the concentration of an exhaust gas component, and an engine condition correction factor is selected from a memory in which a plurality of engine condition correction factors are prestored in the form of a table. The engine condition correction factor is renewed in accordance with the variation in the value of the integration correction factor so as to perform learning control. In order to prevent each of the engine condition correction factors from assuming an undesirable value which are far deviated from its standard, a constant or variable limit value is set. The limit value may be set by calculating some typical engine condition correction factors.

Abstract: A fuel injection control device includes a microcomputer which determines a fuel injection amount based on the engine operation parameters. The microcomputer also actuates the fuel injection valve to open earlier in relation to the normal timing of fuel injection in response to turning on the starter switch. The fuel injection amount corresponds to the duration of opening of the fuel injection valve, and the opening duration of the fuel injection valve is defined by a driving signal and a stopping signal. The driving signal is generated at given angles of crank revolution. The driving signal is generated in response to a preset number of crank angle pulses, which is varied between the first fuel injecting operation and subsequent fuel injecting operations. The fuel injection timing of the first injecting operation is shorter than that of the remainder for improving start-up characteristics of the engine responsive to turning on the starter switch.

Abstract: An electronic control system for fuel injection into an engine controls an air-fuel ratio at a desired air-fuel ratio during a high load operation of the engine. The electronic control system performs the operations of detecting operating parameters of the engine, computing by a computing unit a time width in accordance with the detected operating parameters, selecting a maximum time width value of the injection pulse from a preliminarily stored table of maximum time width values thereof in accordance with the value of at least one of the detected operating parameters, comparing the computed time width value with the selected maximum time width value, limiting the computed time width value in accordance with the selected maximum time width value, and applying the injection pulse to the fuel injectors, thereby controlling the air-fuel ratio under the high load conditions at a desired air-fuel ratio and also preventing the malfunction of continuous fuel supply from occurring in the fuel injectors.

Abstract: The operation of a motor vehicle is controlled by reading of a programmed memory to accelerate the vehicle along a predetermined optimum efficiency curve. The acceleration is independent of the position of the accelerator pedal, provided the pedal is neither in the idling position nor in the full throttle position. For these positions, the acceleration of the vehicle is not under the control of the programmed device.

Abstract: An air-fuel ratio control system for an automobile engine of a type having a fuel injection system wherein at least two of parameters including the engine speed, the opening of a throttle valve and the negative pressure developed inside a fuel intake passage are utilized to detect the rate of flow of incoming air to be mixed with an injected mist of fuel to form a combustible mixture. The amount of fuel to be injected into the intake passage depends on the detected rate of flow of the incoming air. A composition sensor for detecting the concentration of an exhaust gas component is also provided for controlling an EGR control valve for controlling the recirculation of a portion of exhaust gases from an exhaust passage into the intake passage.

Abstract: A method in a multicylinder engine, for obtaining the single combination of ignition timings for the individual cylinders producing the maximum engine speed. A group of combinations of ignition timings is selected, then the engine is successively operated by each combination. The combination producing the lowest engine speed is determined and replaced by a new combination of ignition timings capable of increasing the engine speed. The new combination is calculated by use of a predetermined formula. This procedure is repeated to obtain the single combination of ignition timings producing the maximum engine speed.

Abstract: A fuel distribution control system for equalizing the amplitude of the torque impulses imparted to the crankshaft of an internal combustion engine having a fuel control computer generating fuel quantity signals indicative of the engines fuel requirements, fuel delivery means delivering fuel to the engine in response to the fuel quantity signals and means responsive to the instantaneous rotational velocity of the engine's crankshaft for generating signals indicative of the amplitude and phase angle of the torque impulses imparted to the engine's crankshaft by the individual cylinder.

Abstract: To reduce the data processing requirements within operating cycles of an automotive-type microprocessor or computer, the input/output unit has an angle increment counter receiving angle increment signals synchronized with rotation of the crankshaft of the engine, the counter providing output signals to comparators which, when the count state reaches predetermined values as applied from a data bus, derived from the microprocessor, to the comparator, then provides output signals to control the engine, for example by providing ignition control output signals, fuel injection control output signals, or the like.

Abstract: An internal combustion engine fuel injection control apparatus is disclosed in which a basic fuel injection signal for light load is calculated as a function of the manifold pressure when the engine is operating with a light load, and a basic fuel injection signal for heavy load is obtained with the revolution number and the throttle valve position as the parameters when the engine is operating with a heavy load. The engine load condition (light or heavy) is decided in dependence upon the throttle valve position or the manifold pressure. The circuit employed for switch-over from a heavy load to a light load or vice versa preferably has a hysteresis characteristic.

Abstract: A compensation value computing method for an electronic fuel injection controlled engine according to this invention measures an operating parameter for detecting the idling, low-load and high-load running conditions of the engine. First, second and third memory locations are provided corresponding, respectively, to these running conditions of the engine to compute feedback air-fuel ratios on the basis of feedback signals from an air-fuel ratio sensor. Values in the memory are compensated corresponding to the detected running conditions of the engine on the basis of the deviation of a feedback air-fuel ratio from the base air-fuel ratio.

Abstract: A fuel control system for a spark ignition internal combustion engine of the type having a source of fuel and a pump for supplying the fuel from the fuel source and to the engine at variable flow rates. The fuel control system of the present invention is particularly suited for a reciprocating piston aircraft engine and is designed to minimize brake specific fuel consumption of the engine during steady state engine operation. The fuel control system utilizes a microprocessor to determine the peak value of the exhaust gas temperature and, once the peak has been found, repeatedly decreases the fuel flow rate to the engine in predetermined increments until the exhaust gas temperature is less than its peak value by a predetemined amount. At this time, the fuel control system maintains a constant fuel flow rate to the engine.

Abstract: For controlling an internal combustion engine for the acceleration of an automobile, a change in the amount of air passing through an intake manifold is detected and a correction for the fuel injection time is performed on the basis of the change. After the amount of air has reached a substantially constant value, the corrective control is continued for a certain period of time.

Abstract: A method for improving fuel control in an internal combustion engine employs a pressure ratio to determine the engine's actual volumetric efficiency continuously as the engine is operating. The air/fuel ratio of the engine's combustible mixture is affected by the volumetric efficiency. The volumetric efficiency varies during engine operation. Determination of the actual volumetric efficiency on a real-time basis allows greater accuracy in fuel metering. The pressure ratio used in the determination of the volumetric efficiency is the ratio of the intake and exhaust pressures or the inverse of this ratio. The ratio of pressures is combined with a second factor representative of the forces acting upon the air or air/fuel mixture inducted into the engine. The pressure ratio may be obtained without actual measurement of the pressure in the engine's exhaust conduit.

Abstract: A fuel injection system for a motor vehicle internal combustion engine includes a controller that energizes an electromagnetic fuel injector for time durations determined to provide the fuel requirements of the engine. The fuel injection system is calibrated to the actual fuel flow rate of the injector by a calibration resistor provided with the injector assembly having a resistance related to the actual fuel flow rate of the injector. The controller samples the resistance of the calibration resistor and retrieves a number related to the actual fuel flow rate of the injector from a lookup table in a memory containing fuel flow rate information at locations addressed by resistance values. The retrieved fuel flow rate information is then utilized to determine the time duration required to energize the injector to obtain the required amount of fuel.

Abstract: A fuel injection timing system for a compression ignition engine makes use of a read only memory programmed to provide a digital output representing the time or shaft angle when injection is required in accordance with the values of digital input corresponding to speed and engine load. The speed data is obtained from a transducer which also provides position signals enabling an injection datum to be established so that a comparator can compare the output of the memory with a digital signal representing shaft angle or time to trigger injection at the required instant.

Abstract: An electronic control device for an automobile is equipped with a circuit for producing a first reset pulse when power is initially supplied to the electronic control device, and a circuit for producing a second reset pulse when the engine is cranked by a starter motor. Thus, an electric digital computer in the electronic control device is initialized in response to not only the first reset pulse but also the second reset pulse.

Abstract: An air/fuel ratio control system for use with an internal combustion engine. The system is provided with an electrical circuit which operatively connects an O.sub.2 sensor with fuel quantity adjusting means in a manner effecting feedback control of the air/fuel ratio of a mixture produced by the fuel adjusting means and being supplied to the engine in response to the output signal of the O.sub.2 sensor. The electrical circuit includes means operable during open loop control of the air/fuel ratio under a particular engine operating condition, for controlling the fuel quantity adjusting means so as to obtain a mixture having a predetermined air/fuel ratio appropriate for the particular engine operating condition, irrespective of the O.sub.2 sensor output signal, and means for correcting the above predetermined ratio in response to atmospheric pressure. The electrical circuit further comprises fail safe means for detecting a malfunction in the atmospheric pressure sensor.

Abstract: This invention relates to a system for the regulation and control of the angle of advance in the ignition unit of an internal combustion engine, which is based on the use of a properly programmed microprocessor unit which receives the input data from a set of detectors of engine parameters, processes them and finally delivers output data representative of the regulated magnitude, that is, of the angle of advance.

Abstract: A method of electronically controlling fuel injection in an engine including a bypass line running in parallel to the portion of an intake passage in which a throttle valve is provided. The communicable cross sectional area of the bypass line is controlled so as to maintain the idling speed of an engine at a predetermined desired value. When the engine temperature is higher than a predetermined value, the engine is idling and the communicable cross sectional area of the bypass line is being controlled, a value is stored related to the mean value of the flow rate of intake air or the mean amount of fuel being injected into the engine. When the engine is later being started, when the engine temperature is lower than a predetermined value, or when the engine is accelerating while the engine temperature is yet lower than a predetermined value, the amount of fuel to be injected is calculated by using the value thus stored as a parameter to compensate for internal friction in the engine.

Abstract: An electronic fuel injection (EFI) control system (10) for an internal combustion engine. The EFI control system (10) is disclosed in conjunction with a compression ignition engine (12) where the parameters of fuel quantity (446) and injection timing (460) are controlled on the basis of a plurality of engine operating conditions. The parameter of fuel quantity (446) is obtained from a comparison of computed values of percent load fuel quantity (428) and full load fuel quantity (444) with the lesser of the two being selected. The percent load fuel quantity (428) has a proportional component (416) that is a function of actual engine speed (414) and commanded engine speed (412), and an integral component (426) that is related to cumulative speed error (422). The full load fuel quantity (444) is a function of actual engine speed (414) and manifold air density (436). The parameter of injection timing (460) is obtained from a summation of two computed quantities for injection advance.

Abstract: A means to set spark timing in accordance with engine speed includes a counter to count clock pulses between engine speed reference pulses. A read-only memory has successive memory locations each storing an addend quantity and a repeats number. An adder unit, including an accumulator, operates to access the memory locations, and to add the addend quantities to the contents of the accumulator repeatedly a number of times equal to the respective repeats numbers. A comparator produces an ignition firing pulse when the contents of the accumulator corresponds with the reference period number provided by the counter.

Abstract: An electronic engine control system (10) utilizing a digital microprocessor (30) for controlling the timing mechanism (13) and fuel pump rack limit (23) to set the engine timing of, and maximum allowable rate of fuel delivery to, an interval combustion engine (11) so that maximum engine performance is obtained with smoke and emissions limited to required EPA levels. A plurality of timing maps (61-64) are provided, for different modes of engine operation, each map having predetermined value timing control signals programmed therein corresponding to the optimal timing advance of a particular engine speed, or particulaoptimoptimal timing advance of a particular engine speed, or particular combination of engine speed and position of the fuel rack (21). A timing map selector (65) identifies the mode of engine operation and selects the appropriate timing map (61-64) to control the timing mechanism (13) by the particular programmed signal for the existing engine speed and fuel rack position.

Abstract: In a method and a system for engine control an engine control signal is generated on the basis of a signal produced at each moment from at least one sensor for detecting the operating condition of the engine, the control signal being used for engine control. In order to attain the proper engine operating condition, data representative of the detection signal from the sensor is adjusted in advance, and data for correcting the sensor output is calculated from said adjustment value, the correction data being stored in a memory. While the engine is running, the data representative of the detection signal from the sensor is corrected by the correction data stored in the memory, and this corrected detection signal representative data is used to produce the control signal.

Abstract: A fuel control system for an internal combustion engine with correction for optimum values based on a variety of factors. Characteristic engine data is stored in preferably digital memories with capabilities for interpolation. Upon addressing the engine data fields with input signals related to current operational variables, for example the accelerator pedal position, the control system derives therefrom a nominal air flow rate which is used as the reference value in a control loop that sets the amount of recycled exhaust gas and the fresh air flow. As the actual air flow rate approaches the reference value, the fuel flow is adjusted to insure correct mixtures at all times. In another embodiment, the fuel is supplied on demand but cannot exceed a maximum value except under special override conditions. Several other embodiments and variants are presented.

Abstract: The calculation of an adjustment value, which is determined by the concentration of oxygen in the exhaust gas, the opening of a throttle valve provided in an intake air passage to the engine, the engine temperature, etc., is started every time a predetermined number of repeatedly produced start signals, the repetition rate of which corresponds to the rotational speed of the crankshaft, occur. A basic value for fuel supply, T.sub.p =k Q/N, is calculated from the engine operating parameters; the amount of flow of intake air into the engine, Q the rotational speed of the crankshaft, N, and a constant k, and adjusted according to the adjustment value to obtain a control output signal, in the vicinity of the next start signal after said predetermined number.

Abstract: An electronic fuel injection control system adapted for combination with a fuel injection valve, which comprises means for regulating the valve opening pressure of the injection nozzle of the fuel injection valve, means for regulating the injection timing of the injection nozzle, means for detecting the operating condition of an engine associated with the fuel injection valve, and means responsive to the output of the detecting means for electronically controlling the valve opening pressure regulating means and the injection timing regulating means. The electronic control means is adapted to control the valve opening pressure regulating means and the injection timing regulating means so as to obtain an injection rate, an injection timing and an injection period appropriate for the operating condition of the engine.

Abstract: A fuel injection valve of an internal combustion engine is opened at a predetermined crank angle position. A counter starts to count pulses from a clock pulse signal generator at the predetermined crank angle position, and produces a signal to close the fuel injection valve when the accumulated count in the counter reaches an integer value which corresponds to the ratio of Ti to Tc where Ti is the fuel injection time duration, calculated by a calculating means from engine operational parameters, and Tc is the period of the signal from the clock pulse signal generator. The clock pulse signal generator is controlled by the calculating means, and the period Tc of its output signal is thereby varied. The ratio of Ti to Tc should preferably be selected so as to be as close to the capacity of the counter as possible.

Abstract: An engine control system is provided with a memory having an area addressed by two parameters chosen out of a group of throttle valve position, manifold pressure and engine rotation number, memorizing digital forms of predetermined fuel injection quantities plotted at points separated with a given distance. The values stored in those areas are read out to give a digital form of fuel injection quantity addressed with said parameters introduced by the sensors during the engine operation. The read-out value is multiplied by a coefficient concerning at least one of such detected values as air pressure, aspirated air temperature and engine temperature in order to give a corrected quantity with which the fuel injection is controlled. In this invention the digital controlling quantities stored in the first memory are plotted with short interval and high accuracy where the throttle opening angle is small and the interval is increased with increasing throttle opening angle.

Abstract: A method and a system for engine control are disclosed. Electrical signals representing the engine operating conditions are detected, which electrical signals, together with the control data stored in a memory, are used to calculate a correction factor for correcting the control data for controlling the engine, where the correction factor is stored in a volatile memory, thus controlling the engine on the basis of the control data corrected by the correction factor. The correction factor stored in RAM is transferred to a non-volatile memory under predetermined conditions. Even if the voltage applied to RAM is reduced to a level lower than the storage ability of RAM, resulting in the loss of the stored data, the correction factor stored in EAROM is transferred back to RAM upon restoration of a normal voltage at RAM.

Abstract: An apparatus for controlling an air-fuel ratio of a combustion engine with a memory device for storing correct values for air-fuel control in accordance with an intake condition of said combustion engine and a rotation speed of the same. In the apparatus, an air-fuel ratio represented by the exhaust gas composition of the internal combustion engine is sensed and the sensed value is integrated. When the integrated value from the integrator fails within a predetermined range of values, one of the correction values for the air-fuel ratio control is corrected in accordance with a current condition of the internal combustion engine. When the integrated value falls outside the predetermined range, the correction values are replaced by a predetermined reference value and an air-fuel ratio of mixture supplied to the combustion engine is controlled in accordance with the correction values for the air-fuel ratio stored.

Abstract: This invention relates to a regulation and control system for the fuel feeding unit of an internal combustion engine, said system being based on the use of a microprocessing unit which has properly been programmed. A set of detectors of engine parameters supplies the microprocessing unit with a set of input data which are processed in the processing unit and converted into a set of output data which are representative of the regulated magnitudes, more exactly of the duration and phase setting of the fuel feed.

Abstract: During operation of an internal combustion engine at low temperatures, the carburetor choke is closed to the extent necessary to provide the fuel which will maintain the mean effective pressure of combustion equal to the mean effective pressure occurring during operation at normal temperatures. The torque produced during low temperature engine operation is thus maintained equal to the torque produced during operation at normal temperatures.

Abstract: A method for preventing overheating of an exhaust purifying device by means of an air-flow sensor for sensing the amount of air drawn into an engine to generate an analog voltage corresponding to the amount of air drawn, an intake-air temperature sensor for sensing the temperature of the air drawn into the engine to generate an analog voltage corresponding to the temperature of the air drawn, a water temperature sensor for sensing the temperature of the engine cooling water temperature to generate an analog voltage corresponding to the cooling water temperature, a temperature sensor mounted on a converter, an RPM sensor for sensing the rotational speed of the engine to generating a pulse signal of a frequency corresponding to the engine speed, and a circuit responsive to the detection signals from the sensors for computing the desired amount of fuel injected. The computing circuit controls the ON and OFF periods of fuel injection valves to adjust the fuel injection quantity.

Abstract: A fuel injection rate control system for a fuel-injection internal combustion engine, wherein basic fuel injection rate signals are produced upon detection of the load on the engine and the engine output speed and are modified by the correction values read out from a collection of data indicating various correction values in terms of the engine output speed and the engine load. When the correction values selected are zeros or smaller than a predetermined value, the fuel injection rate may be controlled to achieve a predetermined air/fuel ratio in the engine through detection of the air/fuel ratio of the mixture produced in the engine.

Abstract: A fuel supply control system is disclosed which uses a stored program type digital computer for calculating a basic amount of fuel and modifying the basic amount in accordance with various correction factors dependent upon engine operating conditions so as to determine an actual amount of fuel supplied to an engine. The actual fuel amount is determined by adding all correction factors dependent upon engine temperature and multiplying the sum by the basic fuel amount.

Abstract: An electronic engine control apparatus controls the engine on a basis of the outputs of the digital processor which arithmetically processes output signals from plural sensors for detecting the operating conditions of the engine. Whether or not a pulse to be generated in timing with the rotation of the engine has been generated within a preset period of time, as specified by the digital processor, is checked. If the pulse is generated, a timer for measuring the preset period is cleared. If the pulse is not generated within the preset period, a signal indicating the stopping of the engine is generated, whereby an interrupt signal is generated to cause the digital processor to process the interrupt.

Abstract: An air/fuel ratio controller for an internal combustion engine including two memories each having numbers stored at locations addressed by engine operating points with the locations addressed by the engine operating points being updated during closed loop operation in accord with the value of a closed loop adjustment of the air/fuel ratio. Each memory location in the first memory is updated during operation of the engine at the corresponding operating point in accord with an update time constant having a value so that the number stored tracks adjustment value producing the predetermined desired closed loop air/fuel ratio during varying values of engine operating parameters. Each memory location in the second memory is updated during operation of the engine at the corresponding operating point in accord with an update time constant having a value so that the number stored is the average of the values producing the predetermined closed loop air/fuel ratio during varying values of engine operating parameters.

Abstract: An air/fuel ratio controller for an internal combustion engine including a memory having numbers stored at locations addressed by engine operating points with the locations addressed by the engine operating points being updated during closed loop operation in accord with the value of a closed loop adjustment of the air/fuel ratio. Each memory location in the memory is updated during operation of the engine at the corresponding operating point in accord with an update time constant having a value so that the number stored tracks adjustment value producing the predetermined desired closed loop air/fuel ratio during varying values of engine temperature. The update time constant is varied directly with the value of engine temperature so that the rate of adjustment of the numbers in the memory is greater during engine warmup where engine temperature increases rapidly. The memory is used during closed loop operation to preset the closed loop adjustment at least when the engine first operates at an operating point.

Abstract: A fuel control system is provided for a spark-ignition internal combustion engine having a source of fuel and means for supplying the fuel from the fuel source and to the engine at variable flow rates. The fuel control method of the present invention is particularly suited for a reciprocating piston aircraft engine and is designed to minimize brake specific fuel consumption of the engine during operation at constant engine rotational speed and load but is capable of supplying additional fuel to the engine during transient operation, for example during an acceleration phase. In brief, when the engine is operating under constant engine rotational speed and load, an engine parameter, such as the exhaust gas temperature, which is correlated to the brake specific fuel consumption for the engine is iteratively sensed and compared to the previously determined value for this parameter.

Abstract: An internal combustion engine having a plurality of cylinders is provided with a fuel supply system of a single point injection type, a fuel supply control apparatus controls at least one of operation initiating timing and operating duration of a fuel injection valve for at least one of the cylinders independently from the other cylinders, to thereby optimize the distribution of fuel supply to each of the cylinders.

Abstract: A device is proposed for determining a fuel metering signal for an internal combustion engine comprising a tachometer, a load detector, as well as a storage element and a summing member. The load signal is preferably selected at certain times and then stored temporarily, wherafter the load signal is optionally corrected, multiplied with a time interval, and the sum total of the multiplication results represent a value with respect to the metering signal. Preferably, the signals are processed in a digital fashion, and the load signal is corrected after having been digitized. This is done because for example, in case of a hot-wire air flowmeter, there is no linearity between air flow (air mass flow) and the output signal of the air flowmeter.

Abstract: A method and an apparatus for controlling an internal combustion engine employs a scheme whereby the operating conditions of the engine for normal operation are detected. Desired set values representative of the desired operating conditions of the engine are calculated on the basis of the detected operating conditions, and the desired set values are set in respective reference registers. The contents of one of instantaneous registers for storing instantaneous operating conditions of the engine respectively corresponding to the desired set values are successively compared with the desired set value stored in the corresponding one of the reference registers and a control signal is supplied in accordance with the result of each comparison to control the operation of the engine so that optimal operation of the engine may be performed.Prior to the starting of the engine, a preset scenario or procedure is carried out in response to the turn on of the key switch.

Abstract: A method for operating an internal combustion engine under varying load conditions includes different controls which are used in first, second and third load ranges of the engine. In the first, lowest load range, including idle operation, a constant lean fuel-air ratio and constant mixture volume are supplied to the engine while the ignition timing is varied to provide a more advanced timing with increased engine load. In the second, intermediate load range, the lean fuel-air ratio is again maintained constant, the ignition timing corresponding to the most advanced ignition timing of the first range is maintained constant, and the mixture volume is varied from the volume corresponding to the first range to a higher volume with increased engine load. In the third, highest range of engine load, the mixture volume is maintained constant, the ignition timing is varied only as required to prevent knocking of the engine, and the fuel-air ratio is varied to supply a richer mixture with increased engine load.

Abstract: A digital advance control system of the type including a digital computer which receives input data of various engine operating parameters including the number of pulses corresponding to the ignition angle from a tachometer device in which the data from the tachometer device is to be interpolated. The data to be interpolated is applied to an attenuator circuit which includes a subtracter which receives the higher order bits of the data and a reversible counter whose higher order bits are also applied to the subtracter. The output of the subtracter is applied to a preselection counter or a binary rate multiplier which controls the application of clock pulses to the reversible counter.

Abstract: An input-output unit carries out some of the operations previously carried out in the microcomputer controlling the ignition, injection, etc. processes so that the number of bits in the microprocessor can be reduced. The input-output unit includes a counter which furnishes speed-dependent or angle-dependent signals. During a predetermined angle of rotation or while a particular speed-dependent value is counted and down, a frequency proportional to the quantity of air in the air inlet is counted, the resultant air number transferred to the microprocessor where it is modified. The modified air number can be counted down in the same counter which was used to count down the speed-dependent signals. The time required for counting down the modified air number determines the injection time and/or the closing time for an electronic switch in the primary circuit of the ignition coil.

Abstract: A system for providing acceleration enrichment in a vehicle engine fuel injection system is enabled by a sensed transition from a transmission neutral condition to a transmission drive condition to enrich the mixture supplied to the engine to provide improved engine performance.

Abstract: A method and apparatus for controlling the various functions of an internal combustion engine using a program-controlled microprocessor having a memory preprogrammed with various control laws and associated control schedules receives information concerning one or more engine-operating parameters such as manifold pressure, throttle position, engine coolant temperature, air temperature, engine speed or period and the like. These parameters are measured and their values are supplied to input circuits for signal conditioning and conversion into digital words usable by the microprocessor. The microprocessor system computes a digital word indicative of a computer-commanded engine control operation and output circuitry responds to predetermined computer-generated commands and to the computed digital command words for converting them to corresponding pulse-width control signals for controlling such engine operations as fuel-injection, ignition timing, proportional and/or on-off EGR control, and the like.

Abstract: A method and apparatus for controlling the various functions of an internal combustion engine using a program controlled microprocessor having a memory preprogrammed with various control laws and associated control schedules receives information concerning one or more engine-operating parameters such as manifold absolute pressure, throttle position, engine coolant temperature, air temperature, engine speed or period and the like. These parameters are measured and their value or status is supplied to input circuits for signal conditioning and conversion into digital words usable by the microprocessor.