Abstract: A direct-injection internal combustion engine is controlled such that an injection count of multiple-stage injection is switched according to an operating region, and the multiple-stage injection is performed. The multiple-stage injection divides fuel into multiple times in one combustion cycle, and injects the fuel. Fuel vapor generated in a fuel tank as evaporated fuel is supplied to the internal combustion engine. An operating region in which the injection count of the multiple-stage injection is large is controlled to be narrower when an amount of the evaporated fuel supplied to the internal combustion engine is large, compared with a case of the amount of the evaporated fuel being not large.

Abstract: A GDCI engine control system includes a fast electric heater located within a pocket in a cylinder head. The pocket is in fluid communication with multiple intake ports. A heater control system includes a capacitor that is configured to provide a voltage that is greater than battery voltage to more quickly heat the intake air during a cold start. Subsequently a lower voltage can be supplied to the heater.

Abstract: A technique for correcting injector characteristics is provided. In particular, a micro control unit is configured to generate a control pulse for controlling the operation of an injector; and a driving semiconductor is configured to detect and calculate a driving characteristic of the injector and compensating for injection timing of the control pulse in accordance with a deviation in injection timing of the injector.

Abstract: A control device for generating a second trigger with a delay of a predetermined time from generation of a first trigger, the control device having: a counter for counting numbers from 0 to n?1 at a frequency with cycles of a first period; a control section, which operates at a frequency with cycles of a second period that is longer than the first period, for calculating a remainder of a division by adding a number of counts of the counter corresponding to the predetermined time to a count value of the counter at the time of generation of the first trigger and by dividing a result of the addition by n; and an output section for outputting the second trigger at a time when the count value of the counter becomes equal to the remainder.

Abstract: In an apparatus for controlling an engine, an abnormality determining unit determines whether the crank signal is abnormal based on a state of a input signal for an interval measuring unit. The interval measuring unit measures a time interval from when a predetermined-directed level change appears in the input signal and a temporally next predetermined-directed level change appears therein. An input unit switches the input signal for the interval measuring unit from a crank signal to a cam signal when it is determined that the crank signal is abnormal. The crank signal has a level that repetitively changes in a predetermined direction each time the crankshaft rotates by a first angle. The cam signal has a level that repetitively changes in time in a predetermined direction each time the camshaft rotates at least by a second angle different from the first angle.

Abstract: An engine start control system provides at least one sensor detecting engine operating conditions, an injector, and a control unit. The control unit controls the injector based on signals of the at least one sensor and it is programmed to perform a control logic comprising, determining whether an accumulated number of cases in which engine start is determined to be delayed is greater than a predetermined reference value and controlling the injector to not inject fuel for a predetermined number of engine cycles.

Abstract: A system and method to predict engine air amount for an internal combustion engine is described. Included is a method to predict a change in engine air amount based on engine position. This method especially suited to engine starts, where engine air amount is difficult to predict due to low engine speed and limited sensor information. The system and method provides the prediction of engine air amount without extensive models or calibration. Fuel is supplied based on the predicted engine air amount.

Abstract: A method to deliver fuel during a start for an internal combustion engine is described. The method provides individual cylinder fuel control based on the number of fueled cylinder events. The method offers improved engine emissions while maintaining engine run-up performance.

Abstract: An engine start control system provides at least one sensor detecting engine operating conditions, an injector, and a control unit. The control unit controls the injector based on signals of the at least one sensor and it is programmed to perform a control logic comprising, determining whether an accumulated number of cases in which engine start is determined to be delayed is greater than a predetermined reference value and controlling the injector to not inject fuel for a predetermined number of engine cycles.

Abstract: A system and method to predict engine air amount for an internal combustion engine is described. Included is a method to predict a change in engine air amount based on engine position. This method especially suited to engine starts, where engine air amount is difficult to predict due to low engine speed and limited sensor information. The system and method provides the prediction of engine air amount without extensive models or calibration. Fuel is supplied based on the predicted engine air amount.

Abstract: In an engine control unit, a crank signal is generated as a pulse train of every predetermined angle interval corresponding to rotation of a crankshaft of an engine. An edge time measuring counter receives the crank signal and measures an interval of pulses. A frequency multiplication counter generates frequency multiplication clocks of integer times by the next pulse on the basis of a pulse interval of this time. A reference counter counts the number of waves of the frequency multiplication clocks between pulses in the crank signal. When the count value of the reference counter reaches a frequency multiplication number, a guard counter forcedly stops outputting of angle clocks which are outputted in response to generation of frequency multiplication clocks in a tracking counter.

Abstract: The present invention provides a control apparatus for controlling an internal combustion engine that enables preferable acceleration in response to the running status of the internal combustion engine. When a computer which computes the fuel supply of the internal combustion engine at each engine cycle according to engine parameters detects a change in the throttle opening level of the internal combustion engine from a low opening level which is lower than a predetermined opening level to a non-low opening level which is higher than the predetermined level and when the computer detects that a variation &Dgr;&thgr;TH in the opening level of a throttle is equal to or greater than a predetermined value, the computer generates different increment correction values and corrects fuel supply according to the increment correction values.

Abstract: The present invention relates to the synchronization of an internal combustion, four-stroke engine during engine startup. The engine comprises a number of cylinders with pistons linked to a crankshaft, means to provide a series of pulses on each cycle of the engine, and an engine management system that includes: a memory; means to determine the engine cycle after the engine is cranked; and means to count thereafter the series of pulses until the engine comes to a stop in order to determine the engine cycle of the engine when subsequently stopped so that data representative of the engine cycle may be stored in the memory. According to one aspect of the invention, the means to determine the engine cycle after the engine is cranked is a means to determine the engine cycle during running of the engine.

Abstract: A digital degree wheel is provided including an engine sensor mounted to at least one of a camshaft, distributor and crankshaft of a vehicle for generating an activation signal after the detection of the rotation thereof. An ignition sensor connected to an ignition of the vehicle for generating a deactivation signal upon the detection of the advancing of the ignition of the vehicle. A display connected to the ignition sensor and the engine sensor for displaying a plurality of numeric digits representative of a timer, which is adapted to begin upon the receipt of the activation signal and further cease upon the receipt of the deactivation signal for setting and checking the ignition and valve timing of an engine of the vehicle.

Abstract: Disclosed is a control system and method of a two cycle direct fuel injection engine capable of smoothly suspending combustions in the cylinder during light load operation of the engine. Based on a map parameterizing the engine speed and the target engine load, it is judged whether or not, when the engine load is in the light load condition, the target engine load is located in a suspending area in which misfires tend to occur. If the target engine load is not in the suspending area, since there is no possibility of misfire, the normal combustion cycle continues to operate. On the other hand, if the target engine load enters into the suspending area, the control system instructs the fuel injection and ignition apparatuses so as to suspend fuel injection and spark ignition with a frequency determined according to the magnitude of the engine load. The frequency is determined by a predetermined formula such that it is reduced as the engine load becomes high and is increased as the engine load becomes low.

Abstract: An electronic timing system for producing precise timing control signals to the fuel injectors and ignition coils of an internal combustion engine. The system includes a cylinder cycle marker circuit (16) for generating an engine cycle reference signal based on the detected operational position of the engine as indicated by a TDC signal and a fly wheel teeth (FWT) signal. The system also includes a cylinder sequencer (22) for controlling the sequence of combustion in respective cylinders of the engine responsive to the engine cycle reference signal. A multiplying circuit (14) is provided for multiplying the incoming FWT signal to produce a high resolution engine rotation signal which is a programmable integer multiple of the FWT signal. Injector and ignition timing control signals can be delayed by timers (24, 26) with a programmable delay specified in terms of an integer multiple of the multiplied FWT signal, and can therefore be precisely set in terms of .degree.

Abstract: The present invention relates to an electronic meter circuit for a time comparison measurement between two successive periodic events with which the signal time ratios between two times two successive events can be recognized by a simple method.The electronic meter circuits comprises a reference meter to be loaded with a reset value when a first event occurs and for reference meter to start to count at a clock frequency and when a second event occurs, reference meter starts to count in the opposite direction at a clock frequency until a third event occurs, and when the third event occurs, meter reading forms a reference value for the ratio of the signal times between the occurrence of the first and second events and between the second and third events.

Abstract: An altitude determining apparatus for an automotive vehicle includes a calculating part for determining a reference flow rate based on a throttle angle of a throttle valve and an engine speed of an internal combustion engine of the vehicle, the throttle angle being sensed from the throttle valve arranged in an intake passage of the engine and the engine speed being sensed from the engine, a correction part for detecting an operating condition under which additive gas is supplied to the intake passage downstream of the throttle valve and for changing the reference flow rate determined by the calculating part to a second reference flow rate according to the operating condition only when the above mentioned operating condition is detected, and a discriminating part for comparing an intake air flow rate sensed at an inlet portion of the intake passage with a reference flow rate supplied from the correction part and for determining an altitude condition of the vehicle based on the result of the comparison.

Abstract: An apparatus and method for controlling an internal combustion engine can perform exact timing control for ignition timing, fuel injection timing and the like in an inexpensive manner. A crank angle sensing means 20 generates a crank angle signal .theta. comprising a series of successive pulses in synchronization with the rotation of the engine. A cylinder pressure sensor 21 senses an internal pressure in at least one of cylinders of the engine and generates a corresponding cylinder pressure signal P. A pressure peak detecting means 42 detects a peak in the internal pressure in the at least one cylinder during an engine cranking cycle. A reference position setter 43 sets as a reference position the crank angle signal at the instant when the pressure peak in the at least one cylinder is detected. A control timing setter 44 includes a position counter for counting the number of pulses in the crank angle signal. The counter is reset in response to an occurrence to the reference position.

Abstract: The device for monitoring the combustion state of each cylinder is provided in a multi-cylinder engine and determining if combustion abnormality occurs in the cylinder. The misfiring determining circuit compares an engine speed of a previous interval with that of a current interval, calculates the speed variation of a cylinder between both intervals, and determines the misfiring level by comparing the variation with the misfiring determining level. A cylinder misfiring time counting circuit counts the misfiring time of each cylinder and informs a cylinder misfiring time calculating circuit of the counting result. The cylinder misfiring time calculating circuit serves to average the misfiring time. A cylinder abnormal misfiring determining circuit compares the average misfiring time with a predetermined misfiring time maximum value for detecting the abnormal misfiring in each cylinder.

Abstract: A control apparatus can electronically control the operation of a multi-cylinder engine in a precise manner. A first signal generator 1 and a second signal generator 2 are provided on a camshaft operatively connected with a crankshaft for generating a cylinder identifying signal SC and a reference position signal ST, respectively, in synchronism with the rotation of the camshaft. A pulse signal generator 6 or 12 is provided on a crankshaft for generating a pulse signal P of a high frequency in synchronism with the rotation of the crankshaft. The reference position signal ST contains a series of pulses each indicative of a first and a second reference position for each cylinder which are modified by counting the number of pulses in the pulse signal P to provide exact reference positions. A microcomputer 5 or 15 controls the engine based on the exact reference positions of each cylinder thus obtained.

Abstract: Auxiliary control is used to reduce the processing load of an engine control computer by directly controlling a fuel injection system of an internal combustion engine. After initial set up, an auxiliary controller is able to control up to eight injectors while only receiving delay times from engine operating events, e.g. power stroke of each associated cylinder, and pulse width time periods defining the activation times for the injectors. The auxiliary controller can also maintain limited engine operation in the event of failure of the engine control computer when the computer is unable to provide updated delay times and pulse width time periods. A delay time and a pulse width time period are continuously calculated by the engine control computer and provided to the auxiliary controller. The most recently received delay time and pulse width time period are then used by the auxiliary controller to control up to eight identified fuel injectors.

Abstract: The invention is a pulsed, hydraulically actuated fuel injector ignitor system for an internal combustion engine with combustion chambers and a fuel injector, comprising an outer shell containing a fuel inlet cavity, a fuel supply and scavenging chamber supplied with fuel from the inlet cavity through the rod bore of the injector rod, and a fuel pressure chamber, which is resupplied through check valve from the supply chamber after each injection has taken place. The pressure chamber has a poppet valve responsive to a predetermined fuel pressure in the pressure chamber, resulting from the intrusion of injector piston into the pressure chamber, thereby spraying fuel into the combustion chamber through a hot-throated venturi and igniting the fuel as it passes through venturi. Concentric open-ended cylinders form the control body assembly and are positioned between the base assembly and the fluid manifold head cap and having alternate open-ended cylinders in communication with sliding contact.

Abstract: A data communication control system includes first and second control units each having a microcomputer, the second control unit carrying out a first interrupt processing which starts in accordance with a first timing signal having a first period, and a second interrupt processing which starts in accordance with a second timing signal having a second period, the second interrupt processing being for the second control unit to receive data transferred from the first control unit. The second timing signal is generated in the first control unit in such a manner that adjacent ones of the second timing signal have values of the second period different from each other. Therefore, even if the first interrupt processing and the second interrupt processing conincide with each other the coincidence is not continued whereby transfer of data can be reliably carried out.

Abstract: In a control apparatus for an internal combustion engine for receiving outputs of a crank angle sensor, air flow sensor, etc., calculating control values from these outputs using a microcomputer to actuate actuators; calculated timings at which the respective actuators are deactuated are compared in advance with each other, the control value for the actuator which should be deactuated earliest is stored in an output compare register, and a deactuation signal for the actuator is generated with count matching of two inputs to a comparator of the output compare register. Thus the respective actuators are sequentially controlled.

Abstract: A method of controlling a plurality of electrical devices which control an operation of an internal combustion engine wherein an operation period of time required for each of the electrical devices is computed by computing means in response to operating conditions of the engine, the computed required operation period of time is counted by time-counting means, and each of the electrical devices is caused to operate during the counting. At each start of the time-counting from the computing means, a different one of the electrical devices is selected and the operation thereof is started, an interrupt signal is generated when the time-counting means has counted up, and the operation of the selected different one of the electrical devices is deenergized in response to the generation of the interrupt signal. Preferably, the time-counting means comprises a signal time counter.

Abstract: In an internal combustion engine with combustion chambers (CC'S) (538), a fuel injector (FI) comprising an outer shell (628) containing a fuel supply cavity (FSC) (530) having an openable valve (546) for storing fuel, a control body assembly (CBA) (520) within the outer shell (628). A rod (512) extends from FSC through CBA along the length of the outer shell with piston (518) formed thereon. An internal bore (534) extends therethrough from the side of a closed end of rod (512) which is movable into the FSC for carrying fuel from the FSC to the CC. A rod supporting base assembly (562), responsive to a predetermined CC pressure increase causes rod (512) to enter FSC, closing valve (546) to cease fuel from entering FSC and exposing bore (534) to force the pressurized fuel in the FSC down bore into the CC. Concentric open ended cylinders (OEC'S) (510) are positioned between the CBA and the base assembly with alternate OEC'S (514) secured to CBA and the other OEC'S (516) secured to base assembly (562).

Abstract: In an unthrottled fuel injection type internal combustion engine, a controlled injection logic to generate a first pulse train whose frequency varies with the accelerator position, N cylinder chambers (CCH's) 11, FIG. 1 ), each with a piston, and a distributor (111, FIG. 4) comprising N first devices and a rotor 109 for generating a second pulse each rotation past a first device, N fuel injection/ignition devices (FIGS. 1-2) each having a fuel ignition element (FIE) extending into a CCH to ignite the injected fuel and a fuel injector for injecting fuel towards each FIE at certain time intervals after the rotor passes the associated first device, a first counter for measuring, in time/degree of engine crankshaft rotation (ECR), the time required for M.degree. of ECR, and for determining the rotor angular velocity.

Abstract: Fuel injection is started through a first one of fuel injection valves, and a time counter counts a period of time elapsed from the start of fuel injection through the first one valve. Fuel injection is started through a second one of the fuel injection valves when a predetermined period of time elapses after the start of fuel injection through the first one valve. The fuel injection through the first one valve is terminated in response to completion of counting of the time counter, and the time counter is restarted to count a difference between a desired fuel injection period of time for the first one valve and a desired fuel injection period of time for the second one valve. The fuel injection through the second one valve is terminated in response to completion of counting of the restarted time counter.

Abstract: An electronically-controlled fuel injection system having a synchronous counter which receives main injection time data corresponding to an amount of fuel to be injected synchronously to engine revolutions, and an asynchronous counter which receives increment injection time data corresponding to an amount of fuel to be injected at a selected time interval asynchronously to the engine revolutions, wherein the synchronous counter is operated for a period of time equal to the main injection time data upon receiving a synchronous signal which is generated synchronously to the engine revolutions, while the asynchronous counter is operated for a period of time equal to the increment injection time data upon receiving an asynchronous signal which is generated at the selected time interval, so as to open a fuel injection valve by pulses which are output from the respective counters during the operations thereof.

Abstract: A control system for controlling a DC control motor which controls an internal combustion engine to follow-up a target value varying continuously depending on the operation condition of the engine, the current flowing through the DC control motor being controlled through pulse width modulation.

Abstract: A control system for controlling an actuator which controls operation of an internal combustion engine in compliance with a target value varying continuously depending on the operation condition of the engine.

Abstract: A fuel supply system controls the amount of fuel to form a stoichiometric combustible mixture during a normal operating condition of the engine. The mixture is enriched during a transient condition to lower the exhaust gas temperature and to reduce the heat load on the exhaust system. Fuel enrichment is delayed for a delay time which varies depending on the time interval between successive acceleration cycles, to minimize fuel consumption while avoiding overheating of the exhaust system.

Abstract: The invention is directed to a method for influencing the metering of fuel to an internal combustion engine, wherein the amount of fuel to be delivered to the engine is varied at least in dependence upon the number of revolutions or working strokes of the engine. In this method, the number of revolutions or working strokes of the engine is measured for subsequent storage in a volatile and a non-volatile storage. If a supply voltage failure causes the contents of the volatile storage to be lost, the more essential portion of this number for the engine continues to be available in the non-volatile storage. Embodiments are described explaining how the volatile and the non-volatile storage can be realized and combined. Also, a description is provided as to how the metering of fuel can be influenced in dependence upon the number of revolutions or working strokes of the internal combustion engine.

Abstract: A fuel injection control device for an internal combustion engine including a synchronous injection control means for controlling a fuel injection amount synchronously with a signal generated at every predetermined crank angle in the internal combustion engine, and an asynchronous injection control means for controlling the fuel injection amount according to an output signal from means for detecting a time of acceleration. The asynchronous injection control means is operated when a number of engine revolution measuring means counts a value equal to or less than a predetermined number of engine revolutions and a throttle valve angle detection means generates a signal equal to or more than a predetermined throttle valve angle signal.

Abstract: A fuel injection control device for an internal combustion engine, which enables injection of fuel into separate cylinders to be controlled by only one timer counter, without reference to the number of cylinders, thereby simplifies the configuration of an electronic circuit for the control of the internal combustion engine, and promotes reduction of cost and improvement of reliability.

Abstract: In an electronic fuel injection control system for an internal combustion engine, a first integration circuit is responsive to an angular signal with a time period in inverse proportion to the rotational speed of the engine for integrating the first half of the time period of the angular signal and for producing a first integration signal indicative of a resultant value of the integration, a hold circuit is arranged to hold the value of the first integration signal upon lapse of the first half of the time period and to produce a hold signal of the held value and maintain it for the second half of the time period and the first half of the time period of the following angular signal, a second integration circuit is responsive to the angular signal for integrating the value of an air quantity signal indicative of the quantity of air drawn into the engine at each start of the first and second halves of the time period and for producing a second integration signal indicative of a resultant value of the integration

Abstract: A fuel control system for actuating injection means for controlling small fuel flows is described in a microprocessor based engine control system. The short time duration fuel pulses are sensed and the control system processes the skipping of the injection pulses in the opposite direction of cylinder ignition or precesses skipping around the engine. In one example, in every three fuel pulses, one is omitted and the remaining two are increased in time duration. This processing of the fuel pulses allows each cylinder to omit receiving fuel only once in four engine cycles for a four cylinder engine. Other counts may be used providing that the count is not a multiple of a factor of the total number of cylinders. The increased time duration of the fuel pulses allows actuation of the injector in its linear region of operation.

Abstract: According to the method of the present invention for judging the state of operation of an intake passage pressure detecting device for an engine, first at the time of starting control the intake passage pressure detecting device is regarded as being in a state of failure, then an initial output from the intake passage pressure detecting device is stored, and in case the difference between this stored initial output and a subsequent output from the intake passage pressure detecting device exceeds a predetermined value, it is judged that the intake passage pressure detecting device is in a state of normal operation. Consequently, the state of operation of the above intake passage pressure detecting device can be judged with high reliability, and the reliability of the entire system can be improved to a large extent.

Abstract: A fuel injection means for an internal combustion engine of an automobile is disclosed which comprises a pulse length determination circuit which receives a driving condition signal and develops a signal of a pulse length corresponding to the driving condition, a fuel injection starting signal generator circuit which develops a fuel injection starting signal and a driving signal generator circuit which develops a driving signal of a pulse length corresponding to that of the signal from the pulse length determination circuit. The driving signal thus developed is sent to a fuel injection valve, thereby fuel of a reliably controlled quantity is injected with a reliably controlled timing not only during usual driving condition but also during acceleration.

Abstract: A regulating device is proposed for control variables of an internal combustion engine, in particular for the fuel metering signal and the ignition signal, which has an intervention capability for signals of at least one knocking sensor on the engine via a knocking-signal evaluation circuit; this knocking-signal evaluation circuit includes a frequency recognition circuit and preferably an amplitude recognition circuit, and it detects and evaluates the knocking signal only during specific times or angles relating to the ignition signal. The frequency recognition circuit is realized by means of two counters. The counting range of the first counter marks the value of the upper threshold frequency which can be recognized, while the counting range of the second counter characterizes the frequency band.

Abstract: A method and apparatus for controlling an air-to-fuel ratio of an internal combustion engine in which the air-to-fuel ratio is maintained within a predetermined control width or range even if one or more of the sensors which detect the conditions of the engine necessary to compute the desired air-to-fuel ratio fail. An air flow sensor produces an output signal having a frequency determined in accordance with the air flow rate into the engine, an oxygen sensor disposed in the exhaust manifold of the engine detects whether the air-to-fuel is lean or rich, and a coolant temperature sensor detects the coolant temperature of the engine. Transitions in the output from the oxygen sensor are used to control the integrating direction of an integrator circuit composed of an up/down counter. A predetermined number of integration values are averaged to compute upper and lower limits of the controlled ratio.

Abstract: An electronic engine controller is disclosed for controlling selected operations of an internal combustion engine based upon engine operating parameters. The engine controller comprises a load sensor for generating an analog signal indicative of the value of engine load, and an A/D converter for converting the engine load indicative analog signal into digital form. The A to D conversion is synchronized with engine rotation by a data sampling circuit which includes a first circuit for determining, based upon engine speed, a desired position of an engine crankshaft with respect to an engine crankshaft reference position, and a second circuit responsive to the engine crankshaft rotating to the determined engine crankshaft position for providing a command signal to the A/D converter which thereby initiates the A to D conversion process.

Abstract: An electronic ignition and fuel control system is provided for internal combustion automotive vehicle engines which are of the spark ignition type. The ignition and fuel control system of this invention includes an electronic timing and detector circuit, distributor circuit, clock and command circuit, ignition power circuit and air-fuel control circuit. The clock and command circuit responds to selected positioning of an accelerator control element to provide either a plurality of firing pulses to the engine ignitors in an acceleration mode of operation, or to provide single pulse firing in the case of steady state operation or a deceleration mode of operation. In the ignition and power circuit, individual coils are provided for generating a high voltage firing pulse applied to each of the ignitors that are interconnected with the respective coil.

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: Means for improving the fuel economy and hence efficiency of an internal combustion engine having electronic fuel injection where the amount of fuel delivered to the engine is proportional to the width and frequency of injector pulses. The engine is operated at constant speed and a nominal pulse width is established according to ambient conditions. The pulse width is varied, either increasingly or decreasingly, and the width is measured and stored at one point in time and compared with the width at a later time. If the comparison shows the width at a later time to be narrower than the stored value, variation is continued in the original sense. When the comparison shows that the later value of pulse width is greater than the earlier value, the sense of variation is reversed.

Abstract: Sensor inputs as from an engine load sensor alter the frequency of a pulse providing circuit, the output of which adds counts to those counts provided as a function of engine velocity. The total number of counts is used for determining the instantaneous advance angle in a distributorless ignition system.

Abstract: An engine roughness sensor for generating speed normalized digital roughness signals indicative of the variations in magnitude between successive torque impulses imparted to the engine's crankshaft by measuring the period or time it takes the crankshaft to rotate through the same angle for each torque impulse is disclosed herein. The digital roughness signal is normalized as a function of engine speed by dividing the measured magnitude of each torque impulse by a signal indicative of the engine speed to reduce the magnitude of operator induced variations in the generated roughness signals. In an alternate embodiment, the disclosed engine roughness sensor generates a second difference roughness signal which is the difference between the sequentially generated roughness signals.

Abstract: The advance and retard of the spark ignition in an ignition system of an internal combustion engine is achieved electronically by generating two series of pulses in synchronism with the engine using one series as a reference for maximum advance and the other series to operate a counter to count down the requisite number of pulses beyond the maximum advance point before the spark is initiated, the count of the counter being varied from a computer in accordance with speed and/or load on the engine.

Abstract: An electronic engine control apparatus in which the timing of the ignition and the fuel injection are calculated from a negative pressure in the intake manifold of the engine or the flow rate of suction air and the rotational speed of the engine. A reference register group is constituted of registers for storing the result of the calculation while an instantaneous register group is made up of registers for storing the instantaneous states of actuators. One of the registers of the reference register group and one of the registers of the instantaneous register group are selected according to a stage timing signal so that the contents of the two registers selected are compared with each other.