Abstract: Techniques for implementing and/or operating a pipeline system including a pipe segment, in which the pipe segment includes tubing that defines a pipe bore and fluid conduits in a tubing annulus, a pipe fitting secured to the pipe segment, in which the pipe fitting includes a vent port connected to the fluid conduits in the tubing annulus, and a testing apparatus. The testing apparatus includes a fluid valve connected to the vent port, an upstream sensor fluidly connected between the vent port and the fluid valve, in which the upstream sensor determines a fluid parameter associated with fluid within the fluid conduits in the tubing annulus, and a downstream sensor connected between the fluid valve and external environmental conditions, in which the downstream sensor determines another fluid parameter associated with fluid released from the fluid conduits in the tubing annulus while the fluid valve is in an opened state.

Abstract: Methods and systems are provided for using an engine laser ignition system to take images, in real-time, of a cylinder during combustion and estimate cylinder soot generation. If excess soot generation is determined, cylinder fueling is adjusted by varying an injection pressure, amount, and ratio. An air-fuel ratio of the cylinder is also adjusted in view of exhaust temperature constraints to reduce soot generation.

Abstract: A control device is interposable between an oxygen sensor and an electric control unit of a motor vehicle to receive a voltage signal of the oxygen sensor, alter the voltage signal, and output an altered voltage signal. The altered voltage signal is received by the electronic control unit and causes the electronic control unit to produce fuel injector control signals that provide a richer fuel mixture to the internal combustion engine than what would be provided in the absence of said controller.

Abstract: A system and method is provided for the use of the ion current signal characteristics for onboard cycle-by-cycle, cylinder-by-cylinder measurement, for example soot measurement, load measurement such as indicated or brake mean effective pressure, or fuel consumption measurement in an internal combustion engine. The system may acquire an ion current signal, measures one or more of soot, load, fuel consumption and may control the engine operating parameters accordingly.

Abstract: An engine control system (32) apportions smoke and NOx in engine-out exhaust gas by a strategy (38) that corrects a target percentage for fresh air and a target percentage for exhaust gas to re-calculate a set-point for fresh air mass flow. The target percentage for fresh air mass flow is calculated as a function of engine speed (N) and an engine output torque request (TQI_DRIV).

Abstract: A torque estimation system for a vehicle comprises an operating parameter module, a torque estimation module, and an estimation control module. The operating parameter module determines an estimated engine operating parameter based on engine speed. The torque estimation module estimates engine torque based on the engine speed and the estimated engine operating parameter. The estimation control module provides a plurality of engine speeds to the operating parameter module and the torque estimation module to determine estimated engine torque as a function of engine speed.

Abstract: A control system and method of controlling operation of an internal combustion engine includes a load determination module that determines an engine load, an equivalence ratio module that determines an equivalence ratio, a correction factor module that generates a correction factor based on the engine load, the equivalence ratio, and the engine speed and an engine operation module that regulates operation of the engine based on the correction factor.

Abstract: A method for controlling combustion in an engine is provided. The method comprises under a first condition, adjusting an EGR amount of a total cylinder charge in response to engine out NOx levels being below a first threshold. In this way, NOx levels may be used as feedback to control combustion stability.

Abstract: An engine system may include an engine generating torque through a crankshaft, an exhaust line that exhaust gas of the engine flows, a diesel particulate filter disposed on the exhaust line to trap particulate matters of the exhaust gas, a first pressure difference sensor configured to detect a front/rear pressure difference of the diesel particulate filter, a temperature sensor configured to detect a temperature of exhaust gas flowing into the diesel particulate filter, and a control unit that detects signal form the temperature sensor and the first pressure difference sensor in a predetermined rotation cycle of the crankshaft, uses the detected signal to calculate a front/rear pressure difference of the diesel particulate filter, and calculates a temperature of exhaust gas flowing into the diesel particulate filter. A corresponding signal processing method is also described.

Abstract: A method and control system for controlling an engine during diesel particulate filter regeneration includes a diesel particulate filter (DPF) regeneration request module that generates a DPF regeneration request signal. The control system also includes a DPF regeneration control module that controls the oxygen level in the exhaust based on an oxygen level signal corresponding to an oxygen level in the exhaust and a DPF inlet temperature signal corresponding to the DPF inlet temperature.

Abstract: A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a controller in communication with the actuator. The controller is configured to receive a signal indicative of engine speed and compare the engine speed signal with a desired engine speed. The controller is also configured to selectively regulate the actuator to adjust a timing of the engine valve to control an amount of air/fuel mixture delivered to the cylinder based on the comparison.

Abstract: The invention relates to a system for controlling the operation of a diesel engine of a motor vehicle, associated with means for supplying the cylinders with fuel and with means for recirculating waste gases at the admission. The control system comprises means for controlling the supply means according to the rotation speed of the engine and an effective torque control point and means for controlling the recirculating means according to the at least one effective torque control point. The system comprises means for determining a torque control point which is reconstructed from information provided by means for acquisition of the richness of the waste gas of the engine and air supply at the admission thereof and means for adjusting the means for controlling the recirculating means according to the effective torque control point and the reconstructed torque control point in order to minimize the emission of pollutants by the engine.

Abstract: An electronic control unit 30 of a diesel engine 10 stores a relationship between a required fuel injection amount and a corresponding injection command signal. The unit 30 generates the injection command signal corresponding to the required fuel injection amount based on the stored relationship, and drives injectors 20 based on the injection command signal to inject fuel. The unit 30 includes a shifting section, which forcibly changes the engine rotational speed by temporarily shifting the fuel injection mode between a first injection mode and a second injection mode. The first injection mode is a mode in which an after injection is executed after a main injection. The after injection has less fuel injection amount than the main injection. The second injection mode is a mode in which the after injection is not executed.

Abstract: A fuel injection system for an internal combustion engine which is designed to determine an instantaneous engine speed in a cycle of, for example, 30° CA of the engine to learn an actual injection quantity that is the quantity of fuel actually sprayed from a fuel injector. The system filters the instantaneous engine speed using a band-pass filter to extract a cyclic component which varies in synchronism with an engine operating cycle to produce an engine speed change which has arisen from the spraying of fuel into the engine from which unwanted noise components are removed and uses it to determine the actual injection quantity.

Abstract: A diesel engine may be stably controlled without an exhaust gas temperature at an upstream side of a turbocharger, by a method for controlling a diesel engine that includes: detecting an engine rotation speed; detecting or estimating a lambda value; estimating an exhaust gas temperature at an upstream side of a turbocharger by using relationship between the lambda value and an exhaust temperature; determining whether the estimated exhaust gas temperature exceeds a first predetermined reference value; and limiting an engine output power and/or regeneration of a CPF when the estimated exhaust gas temperature exceeds the first predetermined reference value.

Abstract: In an adaptation (4, 5, 6, 7) of differences in injected quantities within high operating ranges, the differences are based on an injection parameter and are determined by regulating an irregular operation in an operating point within the lower operating ranges. The injection parameter which determines the differences in injected quantities in the lower operating point is set on a value different from the normal operating value in this point. The dynamics of the operating point varying with the corresponding parametric value of injection is limited during adaptation (4, 5, 6, 7).

Abstract: A control system for estimating the performance of a compressor is disclosed. The control system has a compressor fluidly connected to an inlet manifold of a power source. The control system also has a power source speed sensor to provide an indication of a rotational speed of the power source, an inlet pressure sensor to provide an indication of a pressure of a fluid within the inlet manifold, an inlet temperature sensor to provide an indication of a temperature of the fluid within the inlet manifold, an atmospheric pressure sensor to provide an indication of an atmospheric pressure, and a control module in communication with each of the sensors. The control module is configured to monitor an engine valve opening duration and an exhaust gas recirculation valve position, and estimate a compressor inlet pressure based on the provided indications, the monitored duration, and the monitored position.

Abstract: To prevent RPM decrease, misfire, and engine stall by refraining from correcting, the amount of fuel to shift an air-fuel ratio toward a lean side to the extent of exceeding a combustion limit when the internal combustion engine operates at a low load, a control apparatus is provided for controlling operation of an internal combustion engine. The apparatus includes an air-fuel ratio state determiner, a characteristic retainer and a fuel correction amount calculator, in which a coolant temperature coefficient of a coolant temperature coefficient characteristic is set to be smaller than a constant value in a region where a coolant temperature is lower than a constant temperature.

Abstract: A misfire detector prevents catalysts from being heated to damaging high temperatures. The misfire detector for a multi-cylinder engine includes a fuel cut control to stop supplying fuel to misfiring cylinders, a control to prevent a fuel feed back control and a fuel learning control and to initialize the correction values of both the fuel feed back control and the fuel learning control, and a retard control to retard the ignition timing based on the extent that misfire occurs or the air-fuel ratio. The retard control can be replaced by a throttle opening control for misfire to limit the throttle opening angle. The retard control can also be replaced by an engine or vehicle speed control to limit the engine or vehicle speed below a predetermined engine or vehicle speed, respectively, irrespective of the throttle position.

Abstract: An engine air-fuel ratio control system is configured to use a rich air-fuel ratio immediately after starting an engine such that the air-fuel ratio converge rapidly toward a stoichiometric value and then afterwards start an air-fuel ratio feedback control. Upon determining an air-fuel ratio sensor is active, a stabilization fuel quantity increasing factor that is a component of a target air-fuel ratio revising coefficient is decreased at a higher rate than the rate used before the air-fuel ratio sensor was determined to be active. Air-fuel ratio feedback control is started when the air-fuel ratio corresponds to a stoichiometric air-fuel ratio. After starting air-fuel ratio feedback control, an unburned fuel quantity compensating value is set based on the stabilization fuel quantity increasing factor in effect at that point in time and added to the target air-fuel ratio revising coefficient while, simultaneously, the stabilization fuel quantity increasing factor is set to zero.

Abstract: In order to average the continuously sampled individual values of the measuring signal through totaling over a summation period (TP1, TP2), said period corresponding to the period, dependent on engine speed, of pressure pulsations of the exhaust, while at the same time sparing the memory resources, it is proposed for totaling to be carried out across the N1 individual values block-by-block and already to start before signal updating so that the block values already formed continuously block-by-block up to the update time (tn) and buffered instead of the respective individual values are used for calculating an average.

Abstract: A method and a device are described for controlling an internal combustion engine. On the basis of the comparison of a setpoint value with an actual value for a variable that characterizes the supplied oxygen quantity, an actuating variable is predefined for controlling an actuating element that influences the fuel quantity conducted to the internal combustion engine and/or the oxygen quantity supplied to the internal combustion engine. The actual value and/or the setpoint value are/is normalized to a reference value.

Abstract: An engine air-fuel ratio control system is configured to use a rich air-fuel ratio immediately after starting an engine such that the air-fuel ratio converge rapidly toward a stoichiometric value and then afterwards start an air-fuel ratio feedback control. Upon determining an air-fuel ratio sensor is active based on the output of the air-fuel ratio sensor and the amount of time elapsed since an engine was started, a stabilization fuel quantity increasing value that is a component of a target air-fuel ratio revising coefficient is decreased at a higher rate than the rate used before the air-fuel ratio sensor was determined to be active. During the same period, an air-fuel ratio feedback revising coefficient is held at a reference value. After the output of the air-fuel ratio sensor reaches a value corresponding to a stoichiometric air-fuel ratio, an air-fuel ratio feedback control is started.

Abstract: A system (400) and method of determining fuel demands of a locomotive engine (10) based upon engine speed and power produced by the engine at a given time, so to optimize the engine's power output for a load while reducing engine emissions. The engine control architecture comprises three interrelated control loops (100–300). A primary feedback control loop (100) employs integral type control with gain scheduling to regulate engine speed to commanded slew rated based upon the locomotive's operator commands. A second control loop (200) provides an active, feed forward or predictive control consisting of a plurality of correction functions each utilizing a Taylor series having coefficients for each term in the series, the coefficients being modified to adapt the system to the engine with which it is used.

Abstract: An engine air-fuel ratio control system uses a rich air-fuel ratio immediately after starting an engine to converge rapidly the air-fuel ratio toward a stoichiometric value. Upon determining an air-fuel ratio sensor is active, a stabilization fuel quantity increasing factor of a target air-fuel ratio revising coefficient decreases at a higher rate than before the air-fuel ratio sensor was active. Air-fuel ratio feedback control starts when the air-fuel ratio corresponds to a stoichiometric air-fuel ratio. Afterwards, when either air-fuel ratio feedback control starts or the engine enters a high rotational speed/high load region that operates using a rich air-fuel ratio, whichever occurs first, an unburned fuel quantity compensating value is set based on the stabilization fuel quantity increasing factor in effect at that point in time and added to the target air-fuel ratio revising coefficient while, simultaneously, the stabilization fuel quantity increasing factor is set to zero.

Abstract: A valve train system for operating an intake valve of an internal combustion engine, in which an operation amount of the intake valve is controlled. When it is determined that there is a need of improving a fuel efficiency by increasing the compression ratio within the combustion chamber on the basis of an engine operating state, an exhaust valve is opened and subsequently closed after an intake stroke until the pressure within the exhaust chamber becomes equal to the pressure within the exhaust passage so as to increase the compression ratio within the exhaust valve.

Abstract: A engine control system and a method of controlling a torque output of an internal combustion engine is disclosed. The engine control system comprises a torque receiving device operably connected to the engine, a sensor to sense an engine parameter, and an electronic device operably connected to the sensor. The electronic sensor is operable to determine a second engine speed from sensed engine parameters, a droop speed, and a selected one of a plurality of torque maps requiring a minimum amount of fuel. The electronic sensor is also operable to transmit a signal indicative of the second engine speed to a fuel system to control the amount of fuel delivered to the engine.

Abstract: An in-cylinder fuel injection internal combustion engine (1) is started up by means of compression stroke fuel injection from the beginning of cranking of the engine (1) to the end of a stratified combustion start-up period TST. If the engine (1) reaches complete combustion during the period, a warm-up operation is begun immediately. If the engine (1) does not reach complete combustion during the period, start-up of the engine (1) is continued using intake stroke fuel injection. By means of this control, stable start-up is assured while suppressing the discharge of unburned fuel during start-up of the engine (1).

Abstract: A diesel engine control system and control method capable of conducting accurate fuel injection unaffected by variations in injector performance caused by differences among individual injectors or change with aging. The diesel engine control system includes an injector for directly injecting fuel into a combustion chamber of a diesel engine, injection quantity controller for controlling fuel injection quantity by varying a period of electric current supply to the injector, estimator for estimating that an electric current supply period when a prescribed (stable) combustion state is obtained is the current supply period for injecting the amount of fuel required for the prescribed combustion state, and control data correcting device for correcting control data of the injection quantity controller based on the estimated current supply period.

Abstract: A system for balancing first and second work outputs between first and second cylinder banks of an engine includes a first intake camshaft associated the first cylinder bank and a first fuel injector associated with the first cylinder bank. A controller trims a pulse-width of the first fuel injector until first and second A/F ratios of respective exhaust of the first and second cylinder banks are equivalent. The controller adjusts timing of the first intake camshaft to effect air flow into the first cylinder bank and trims the pulse-width to maintain equivalency of the first and second A/F ratios.

Abstract: Gas containing fuel vapor is purged as purge gas from a canister to an intake passage through a purge line. An ECU computes purge flow rate, which is the flow rate of the purge gas, and computes vapor concentration, which is the concentration of the fuel vapor contained in the purge gas. The ECU obtains a concentration correction value in accordance with the rate of change of the computed purge flow rate. The ECU correct the computed vapor concentration by using the concentration correction value and by taking into consideration of the time at which the purge flow rate is computed and the time at which purge gas having the computed flow rate is drawn into the combustion chamber. The ECU sets the fuel supply amount in accordance with the computed purge flow rate and the corrected vapor concentration. As a result, the accuracy of the air-fuel ratio control during purging is improved.

Abstract: A method and apparatus for externally modifying the operation of a closed loop electronic fuel injection control system that is normally used with a standard oxygen sensor, which method and apparatus includes replacing the standard oxygen sensor with a wide band oxygen sensor. The signal from the wide band oxygen sensor is processed in a first signal-conditioning module and coupled to the input of the electronic fuel injection control system. The first signal-conditioning module simulates the appearance of a standard oxygen sensor to the electronic fuel injection control system. In a second embodiment, a method and apparatus for externally modifying the operation of a closed loop electronic fuel injection control system that is normally used with a wide band oxygen sensor, includes intercepting the signal from the wide band oxygen sensor in a second signal-conditioning module.

Abstract: A method and apparatus for externally modifying the operation of a closed loop electronic fuel injection control system that is normally used with a standard oxygen sensor, which method and apparatus includes replacing the standard oxygen sensor with a wide band oxygen sensor. The signal from the wide band oxygen sensor is processed in a first signal-conditioning module and coupled to the input of the electronic fuel injection control system. The first signal-conditioning module simulates the appearance of a standard oxygen sensor to the electronic fuel injection control system. In a second embodiment, a method and apparatus for externally modifying the operation of a closed loop electronic fuel injection control system that is normally used with a wide band oxygen sensor, includes intercepting the signal from the wide band oxygen sensor in a second signal-conditioning module.

Abstract: An air-fuel ratio control device for an internal combustion engine is provided with: an air-fuel ratio sensor; an O2 sensor; a device for setting a reference air-fuel ratio target value; a device for setting a target value of an output value of the O2 sensor; a device for obtaining an air-fuel ratio target value correction value; a device for obtaining a forcible air-fuel ratio oscillation width target value; a device for computing an air-fuel ration target value; a device for computing a correction value; a device for obtaining a forcible air-fuel ratio oscillating width injector driving time correction value; and a device for setting injector driving time.

Abstract: Timing of the combustion event in an homogenous-charge compression-ignition engine is controlled by adjusting the reactivity of the fuel, or of the fuel/air mixture inducted into the combustion chamber of the engine, thereby providing a means of controlling the combustion phasing. When the mixture is made more reactive, combustion occurs earlier in the cycle, and when the mixture reactivity is decreased, the reaction phasing is retarded. In the present invention, the reactivity of the intake charge is regulated in one embodiment by using a catalytic reaction in the intake system to partially, oxidize the intake mixture. In another embodiment, fuel reactivity is adjusted by passing a portion of the fuel through a catalyst or a non-thermal plasma generator prior to injection into the engine. In still another illustrated embodiment, an additive is controllably added to the fuel prior to injection into the engine to increase or decrease fuel reactivity.

Abstract: An outboard motor includes a sensor assembly having a housing with a sensor chamber, a sensor having a sensor element exposed to the sensor chamber, and a sleeve disposed in a passage extending from a combustion chamber of the outboard motor to the sensor chamber. The sleeve can have three flanges supporting the sleeve within the passage. Additionally, the sleeve can have an extension so as to allow the overall length of the sleeve to be varied in accordance with the desired resonance frequency of the sensor chamber. An engine of the outboard motor can also include a control system configured to control an air/fuel ratio of fuel charges delivered to a combustion chamber within the engine based on an output of the combustion condition sensor when the engine is in a first operational state and to control the air/fuel ratio, irrespective of the output of the combustion condition sensor, when the engine is in the second operational state.

Abstract: A method providing solution of both of the problem of black smoke during the engine startup period and the problem of undershooting and hunting at the settling time. By adding at least an integral term QI to a basic injection quantity, feedback control of a fuel injection quantity of an engine is carried out. An initial integral term QI0, which is used during the engine startup, is predetermined. During the engine startup period, the integral term QI is set as “0” until an engine revolution number Ne reaches a predetermined startup revolution number Nes. When the Ne reaches the Nes, the initial integral term QI0 is used as the QI. The QI0 is preferably determined on the basis of one of, or both of, a water temperature and an atmospheric temperature. The Nes is preferably a value close to, or equal to, an idling revolution number Nei.

Abstract: An improved engine fuel control detects combustion instability due to the use of high driveability index (DI) fuel during cold start and warm-up and compensates the fuel control for detected combustion instability through temporary enrichment of the delivered air/fuel ratio. The usage of high DI fuel is detected during engine cranking by measuring the time required for the engine speed to increase from a lower reference speed to an upper reference speed, provided the engine run time is less than a calibrated value. A timer is started when the lower reference speed is achieved, and the timer value is compared to a crank time threshold determined as a function of the initial engine coolant temperature. If the timer value exceeds the crank time threshold before the engine speed reaches the upper reference speed, the presence of high DI fuel is indicated, and the air/fuel ratio is temporarily enriched.

Abstract: A method for controlling the titre of the exhaust gases in an internal combustion engine. An oxygen sensor provides a signal indicative of a titre (lambda) of the exhaust gases. The method includes selecting respective values of operating parameters on the basis of an objective lambda value and engine-related parameters, calculating a correction parameter on the basis of the respective values of the operating parameters and the lambda signal and calculating an adjustment quantity of fuel on the basis of the correction parameter and a nominal quantity of fuel. The method further includes selecting respective values of a first and a second of the operating parameters, determining magnitudes as a function of the respective values of the first and the second operating parameters and determining a third of the operating parameters as a function of the first and the second operating parameters and a mean value of the correction parameter.

Abstract: An air-fuel ratio control device for an internal combustion engine is provided with: an air-fuel ratio sensor; an O2 sensor; a device for setting a reference air-fuel ratio target value; a device for setting a target value of an output value of the O2 sensor; a device for obtaining an air-fuel ratio target value correction value; a device for obtaining a forcible air-fuel ratio oscillation width target value; a device for computing an air-fuel ration target value; a device for computing a correction value; a device for obtaining a forcible air-fuel ratio oscillating width injector driving time correction value; and a device for setting injector driving time.

Abstract: A fuel injection control device of an engine having a plurality of cylinders, that prevents sudden change in combustion condition. The control device calculates a basic amount of fuel to be injected into cylinders. The controller then decides an amount of adjustment ultimately made to the basic amount of fuel based on an engine revolution speed difference between the cylinders. The adjustment is stepwise made to the basic amount of fuel so that a total amount of fuel gradually increases or decreases. Since a steep change does not occur in the total amount of fuel, the combustion condition does not change suddenly and the engine does not vibrate.

Abstract: A revolution number control system includes ignition timing delay controlling means for delaying ignition timing from the ignition advance amount n at first prescribed value n2 when the engine revolution number NE is between the first prescribed value n2 and a clutch-on revolution number n4. The first prescribed value n2 is a predetermined revolution number smaller than a present revolution number and the clutch-on revolution number n4 is the present revolution number, and the revolution number control system 40 controls the revolution number by operating the ignition timing delay controlling means when a throttle opening sensor does not detect a change in the throttle opening.

Abstract: An outboard motor engine includes a feedback control system for controlling the air/fuel ratio of the air/fuel mixture combusted within the engine. The control system can be configured to vary the target output value of a combustion condition sensor in accordance with at least one engine operation characteristic, for example, but without limitation, engine speed or throttle position.

Abstract: An internal combustion engine (1), especially for a motor vehicle, is described. The engine is provided with an injection valve (8) with which fuel can be injected directly into a combustion chamber (4) in a first operating mode during a compression phase or in a second mode of operation during an induction phase. A control apparatus (16) is provided for switching over between the two modes of operation and for the different control (open loop and/or closed loop) in the two modes of operation of the operating variables, which influence the outputted torque of the engine (1), in dependence upon a requested torque (mi). The fuel mass, which is to be injected in the first mode of operation, can be determined by the control apparatus (16) in dependence upon the operating parameters of the engine (1) which form the basis of the injections of the second operating mode.

Abstract: In a sliding mode control for restraining an air-fuel ratio state on a switching line set on a phase plane shown by a deviation between an actual air-fuel ratio and a target air fuel ratio, and a differential value of the deviation, an inclination of the switching line is made small, when the smaller an intake air quantity is, the longer a detection delay time of the air-fuel ratio is.

Abstract: An improved engine fuel control detects combustion instability due to the use of high DI fuel during cold start and warm-up and compensates the fuel control for detected combustion instability through temporary enrichment of the delivered air/fuel ratio. The usage of high DI fuel is detected during engine cranking by measuring the time required for the engine speed to increase from a lower reference speed to an upper reference speed, provided the engine run time is less than a calibrated value. A timer is started when the lower reference speed is achieved, and the timer value is compared to a crank time threshold determined as a function of the initial engine coolant temperature.

Abstract: A method for controlling the titre of the exhaust gases in an internal combustion engine, in a control system comprising a control unit and oxygen sensor means, disposed along an exhaust duct of the engine and supplying a signal indicative of a titre of the exhaust gases; the control unit comprising a table, a controller and a correction and actuation block, the table receiving as input a plurality of engine-related parameters and an objective titre value and supplying as output a plurality of operating parameters; the controller receiving as input the operating parameters and the signal and supplying as output a correction parameter.

Abstract: A revolution number control system includes ignition timing delay controlling means for delaying ignition timing from the ignition advance amount n at a first prescribed value n2 when the engine revolution number NE is between the first prescribed value n2 and a clutch-on revolution number n4. The first prescribed value n2 is a predetermined revolution number smaller than a preset revolution number and the clutch-on revolution number n4 is the preset revolution number, and the revolution number control system 40 controls the revolution number by operating the ignition timing delay controlling means when a throttle opening sensor does not detect a change in the throttle opening.

Abstract: A fuel injection control device of an engine having a plurality of cylinders, that prevents sudden change in combustion condition. The control device calculates a basic amount of fuel to be injected into cylinders. The controller then decides an amount of adjustment ultimately made to the basic amount of fuel based on an engine revolution speed difference between the cylinders. The adjustment is stepwise made to the basic amount of fuel so that a total amount of fuel gradually increases or decreases. Since a steep change does not occur in the total amount of fuel, the combustion condition does not change suddenly and the engine does not vibrate.

Abstract: An internal combustion engine includes an improved feedback control system and method for operating the engine to provide the desired air/fuel ratio under all running conditions without causing unsettling variations in engine speed and torque as adjustments to the air/fuel ratio are made. The feedback control operates to modify the fuel/air ratio from that achieved by a basic setting that is derived from parameters of engine performance so as to maintain the desired ratio. The control system also adjust the ignition timing while the air and fuel ratio is adjusted toward the desired ratio to maintain generally constant engine speed and torque.