Abstract: An electronic control unit (ECU) of a fuel injection control system of an internal combustion engine feedback-controls injection timing so that a cylinder pressure maximum value coincides with a target pressure value in an operation range, in which the cylinder pressure maximum value increases as ignition timing advances and torque increases as the ignition timing advances. The ECU feedback-controls the injection timing so that the ignition timing coincides with target timing in another operation range, in which the cylinder pressure maximum value increases as the ignition timing advances but the torque decreases as the ignition timing advances. Thus, the torque can be outputted efficiently by selecting the appropriate feedback control in accordance with the operation range.

Abstract: A method and apparatus for determining a parameter associated with a delivery of fuel in an engine. The method and apparatus includes determining an initial parameter value associated with the delivery of fuel, determining at least one compensation factor based on a heating effect of a fuel and a fuel system, and applying the at least one compensation factor to the initial parameter value to derive a compensated parameter value.

Abstract: Method and apparatus for retrofitting a low impedance fuel injection system to a high impedance fuel injection system internal combustion engine is disclosed. The original high impedance electronic control system may be retained, while system modification circuitry is added along the fuel injector control path. In one aspect, an original fuel injector control signal is intercepted along the fuel injector control wire. The intercepted signal is then modified from a simple on-off signal to a signal which varies the fuel injector current as a function of time, such that the on-state from the original high impedance system is converted to a current controlled signal. Moreover, using a plurality of parameters, the fuel injector pulsewidth may be modified, as well as the peak and hold current levels provided to the fuel injectors.

Abstract: A control system for a low cost, light duty combustion engine, where the control system generally utilizes engine speed and/or temperature input signals and independent operating sequences to determine a desired ignition timing and air-to-fuel ratio for a combustible mixture. There are several independent operating sequences, each one of which is designed to optimally control the engine under certain conditions. These operating sequences include a Cranking sequence that commences after the engine is initially turned on, a Warm Up sequence which follows the Cranking sequence, a Normal Mode sequence for typical operating conditions, an Acceleration sequence for certain increases in engine speed, a Come Down sequence for when a sufficient engine speed is followed by a certain decrease in speed, and a Recovery Bump sequence for when the engine speed dips below a predetermined level.

Abstract: Various systems and methods are disclosed for carrying out combustion in a fuel-cut operation in some or all of the engine cylinders of a vehicle. Further, various subsystems are considered, such as fuel vapor purging, air-fuel ratio control, engine torque control, catalyst design, and exhaust system design.

Abstract: In a method for operating an internal combustion engine, the air-fuel ratio in a combustion chamber is a function of the operating conditions and/or the operating state of the internal combustion engine. It is provided that, with the aid of a data model, a variable expressing a target air-fuel ratio is ascertained from a target torque and an air mass determined with the aid of a model or a measured value, and in addition a setpoint fuel quantity to be injected into the combustion chamber is determined and, using the same data model, a setpoint air mass to be conveyed to the combustion chamber is determined from the target torque and a variable expressing a predefined air-fuel ratio in the combustion chamber.

Abstract: Method for operating an internal combustion engine in which fuel is injected into a combustion chamber by an injector. The injector has a drivable piezo-actuator. A setpoint value is generated for driving the piezo-actuator. A setpoint charge quantity (QCsetpoint) is determined from the setpoint value, and an actual charge quantity (QCactual) supplied to the piezo-actuator is determined. The setpoint charge quantity (QCsetpoint) and the actual charge quantity (QCactual) are combined, and the combined result (Son) acts upon the drive circuit of the piezo-actuator.

Abstract: An electronic control unit (ECU) of an engine calculates a first modification value for decreasing a correction value of an injection period when a state variation of the engine caused by a single injection is greater than a target value. The ECU calculates a second modification value for increasing the correction value when the state variation is less than the target value. The second modification value is greater than the first modification value. Thus, a period necessary to converge the correction value can be shortened when the correction value is increased. The first modification value is increased if a difference between the state variation and the target value exceeds a permissible value when the correction value is decreased. Thus, the injection quantity is decreased quickly to prevent excessive fuel injection.

Abstract: A vehicle traveling through an environmental media such as air experiences drag. The drag is actively modulated by energy beams which may either increase or decrease the drag. The energy beams may provide either a chemical, acoustic or electromagnetic energy at a transition region between turbulent and laminar flows or at the leading edge of a laminar flow or in the direction of a crosswind in order to facilitate the respective increase or decrease in drag. If the vehicle is a sailing ship, areas of the sails are selectively roughened or widened to enhance the thrust derived from the wind. Furthermore, the keel or hull of the sailing ship may be modified to improve the hydrodynamic characteristics of the sailing ship. If the vehicle is an automobile, the tires or road surface may be selectively heated to improve the traction of the automobile.

Abstract: A method of controlling an engine having a valve actuation system is provided. The engine is started. A first parameter indicative of a first temperature of the engine is sensed. A second parameter indicative of a second temperature of the engine is sensed. The valve actuation system is disabled to prevent the implementation of a variation on conventional engine valve actuation timing in response to each of the first and second temperatures being below a predetermined value.

Abstract: The present invention provides a control system for an internal combustion engine for detecting a torque variation based on a rotational speed of the engine and suppress the torque variation. The system includes a detector for detecting a rotational speed of the engine, a memory for storing a variation pattern of the rotational speed of the engine when a torque of the internal combustion engine is excessive and a controller for calculating a variation component of the rotational speed based on the detected rotational speed, The controller calculates the correlation between the variation component and the variation pattern that is read out from the memory and then determines a torque variation state of the engine based on the correlation.

Abstract: A method and a device for storing and/or reading out data of a fuel metering system, in particular a fuel pump or an injector, as described. Data on the fuel pump and/or the injector is assigned to at least one electronic component. The data is taken into account by a control unit in controlling the fuel metering system. The component is mechanically and/or electrically connected to the control unit during a first interval of time and is mechanically and/or electrically detached from the control unit and/or the fuel metering unit during a second interval of time.

Abstract: In an internal combustion engine, the fuel reaches the combustion chamber of the engine via a fuel-injection device which includes a piezo actuator (50). In order to be able to optimally inject the fuel, it is suggested that the desired level (U_DES) of the drive energy (U) and/or the desired gradient (dU_DES) of the drive energy (U), with which the piezo actuator (50) is driven, is dependent upon a plurality of influence quantities (T, t, n, dx, dh) which influence the operating behavior of the piezo actuator (50).

Abstract: A power output stage for capacitive loads includes: an energy storage inductance, having one end connected to a reference potential and an opposite end connected on the input side to a power supply connection and on the output side to a secondary energy storage capacitance; a primary energy storage capacitance is connected upstream of the energy storage inductance on the input side, and connected on the input side via a primary switching element with a reference potential, and a secondary switching element connected in series with the secondary energy storage capacitance (4), characterized in that the input of the power output stage is clocked by an additional switch.

Abstract: An EGR control apparatus for a diesel engine which can stop EGR in advance of increase of a fuel injection quantity when acceleration of the engine comprises: EGR means (4) to adjust an EGR volume which is recirculated from an exhaust pipe (2) to an intake pipe (3); filter means (23) to carry out a smoothening-process to an accelerator opening degree detected by an accelerator opening degree sensor; injection quantity determination means (24) to determine a target fuel injection quantity to be injected from an injector (20), using the accelerator opening degree after smoothening-processed; and control means (25) to calculate a fuel injection quantity for judging EGR stop (Qcut), using the accelerator opening degree before smoothening-processed, to allow the EGR means (4) to carry out a decrease control for the EGR volume when the fuel injection quantity for judging EGR stop (Qcut) exceeds a predetermined threshold value (Hi).

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 charge-injected internal combustion engine exhibits improved starting performance with charge-injection timing control. A charge-injected internal combustion engine has an air-fuel injection valve for directly injecting a compressed air-fuel mixture into a combustion chamber. The engine is also provided with an air pump, driven by the crankshaft for discharging compressed air, and a timing controller for setting injection timing of the air-fuel injection valve. When initial startup of the engine is detected, the controller sets the injection timing to the intake stroke. When the engine reaches a predetermined engine speed, or when the pressure of the injection air reaches a threshold pressure where injection of the air-fuel mixture is possible on the compression stroke, the timing controller switches the injection timing from the intake stroke to the compression stroke.

Abstract: An EGR equipped internal combustion engine is controlled to maximize the beneficial effects and minimize the detrimental effects of EGR on engine operation. Specifically, at least one parameter indicative of the O2 concentration in the intake mixture and/or at least one parameter indicative of the H2O concentration in the intake mixture is monitored, and the monitored parameter is relied on to control one or more aspects of engine operation by open loop adjustment of other control strategies and/or by a separate closed loop control strategy. These controls are applicable to virtually any engine, and are particularly beneficial to lean burn engines such as diesel (compression ignition) engines, spark ignited natural gas engines, and dual fuel or other compression ignited natural gas engines. The engine may be equipped with either actively controllable EGR or passive and uncontrolled EGR.

Abstract: Systems and methods for reducing engine emissions in a locomotive are presented. In an embodiment, a fuel injector or a fuel injection pump of a fuel injection mechanism includes a plunger with an upper helix whose angle changes between points on the plunger that correspond to an idle throttle position and a full throttle position. As such, injection timing is optimized, and engine emissions are reduced.

Abstract: A fuel injection system for an internal combustion engine has an upstream fuel injector provided upstream from the throttle valve and a downstream fuel injector provided downstream therefrom. A device is provided for determining a fuel injection quantity of the upstream and downstream fuel injectors. A sensor detects the intake temperature TA on the upstream side from an injection area of the upstream fuel injector. A device is provided for seeking an intake temperature correction factor KTA on the basis of the intake temperature TA and a fuel injection quantity of the upstream fuel injector. At least one of the fuel injection quantities due to the upstream and downstream fuel injectors is corrected on the basis of the intake temperature correction factor KTA.

Abstract: A system for controlling an engine in a fuel efficient manner includes a memory having stored therein an engine output characteristics map bounded by a maximum engine output curve. The map defines a region of undesirable operation having a first border defined as a function of engine speed and intersecting the maximum engine output curve. A control computer is configured to control engine operation in a fuel efficient manner by limiting engine operation within the map to the first border while also allowing the engine to operate anywhere on the maximum engine output curve. The control computer may be configured to so limit engine operation to the first border only if an engine or vehicle acceleration value is outside of an acceleration range, and further only if an engine work value is greater than an engine work threshold, and otherwise to allow engine operation anywhere on or within the map.

Abstract: An electronic control unit (ECU) of a fuel injection system of an internal combustion engine stores correspondences defining each correspondence between an operating state and a correction value for each progression level of a change in the engine with time in advance. The ECU determines which progression level includes a present state of the change in the engine with time and selects the correspondence based on a result of the determination. Thus, even if a change in an error with time, which should be corrected, does not have an identical tendency corresponding to the operating state, the error can be suitably corrected by referring to the correspondence between the operating state and the correction value in each progression level.

Abstract: A method of controlling fuel injection is disclosed which enables highly accurate fuel injection and an enhanced durability of fuel injection valves in an internal combustion engine using an SPI system. The engine has a plurality of fuel injection valves disposed in an intake passage on an upstream side of a collector portion of an intake manifold of the internal combustion engine so that fuel is supplied to a plurality of cylinders of the engine by fuel injection from the fuel injection valves. The method includes alternately operating the plurality of fuel injection valves so as to supply the fuel when an intake airflow is a low flow rate equal to or less than a predetermined value, and simultaneously operating the plurality of fuel injection valves so as to supply the fuel when the intake airflow is a high flow rate more than the predetermined value.

Abstract: An engine control unit (ECU) of an internal combustion engine performs energy changing control for changing a charging amount (an upper limit value of charging voltage, charging speed or target energy) to a piezo stack of a piezo injector in accordance with common rail pressure. During the energy changing control, the ECU contracts a command injection period as the target energy charged to the piezo stack increases so that actual injection end timing or valve closing timing of a nozzle portion is unchanged even if the target energy is changed. Meanwhile, the ECU delays command injection timing as the target energy increases so that actual injection start timing or valve opening timing of the nozzle portion is unchanged even if the target energy is changed.

Abstract: During a multiple discharges operation, a micro computer changes a discharge period of each discharge in accordance with a pressure transition in a combustion chamber of an internal combustion engine. Thus, the energy amount consumed at each discharge of multiple discharges operation is suppressed toward the minimum requirement, and the consumption of energy accumulated in the ignition device is appropriately controlled. As a result, discharge energy is efficiently consumed at the multiple discharges, thereby compacting the ignition device. Further, the number of multiple discharges is not restricted.

Abstract: A supplying unit supplies energy to an actuator so that the supplied energy is kept therein, making displacement the actuator. An interrupting unit interrupts the supply of energy to cause the actuator to discharge the kept energy, making displacement the actuator. A converting unit is adapted to convert the displacement of the actuator corresponding to the kept energy into hydraulic pressure applied to the valve member, moving the valve member to open the low pressure port and close the high pressure port. The convert unit converts the displacement of the actuator corresponding to the discharged energy into hydraulic pressure applied to the valve member, moving the valve member to open the high pressure port and close the low pressure port. Energy which the actuator requires to move the valve member so as to close the high pressure port is larger than energy which the actuator requires to move the valve member so as to open the low pressure port.

Abstract: A control system enables a considerable decrease in electric power consumption of backup power, leading to effective prevention of a dead battery, while data in each control unit which need be maintained even after power is turned off is properly maintained. An ECU has a first transmitter to transmit data which need be maintained to an ECU for storage when a change in position of an IGSW connected to a battery to the off position is detected, and a power supply cutoff circuit to cut off the power supply to the other ECUs after the completion of the transmission of data to the ECU for storage by the first transmitter, wherein the ECU for storage has a first storage controller to store the data transmitted from the other ECUs in RAM, and a power switching circuit to detect the change of the IGSW to the off position and switch the power of the ECU for storage to the backup power.

Abstract: An engine includes an improved sensor arrangement that can decrease the possibility of damage to sensors relating to fuel injection control. The engine includes a cylinder block defining first and second banks of cylinder bores extending separately from each other. Pistons reciprocate within the respective cylinder bores. Cylinder head members are arranged to close respective ends of the first and second banks of the cylinder bores. The cylinder head members define combustion chambers together with the cylinder bores and the pistons. An air induction system is arranged to introduce air to the combustion chambers. The induction system includes first and second intake units with the first intake unit allotted to the first cylinder bank and with the second intake unit allotted to the second cylinder bank. The first and second intake units define first and second intake passages, respectively, through which the air flows. Fuel injectors are arranged to spray fuel for combustion in the combustion chambers.

Abstract: A method for controlling a diesel engine exhaust gas recirculation system is described. In particular, a simplified diesel engine system is provided where presence of exhaust gas recirculation of flow is controlled via a two-position valve, while a quantity of exhaust gas recirculation is adjusted by varying the throttle valve. In this way, a reduced cost diesel exhaust gas recirculation system is achieved that provides the functionality of having variable amounts of exhaust gas recirculation.

Abstract: A method of estimating an injection delay of a fuel injector. A baseline injection delay curve representing an injection delay for a predetermined type of fuel injector is established for a range of rail pressures. At least one test rail pressure for the predetermined type of fuel injector is identified based on the baseline injection delay curve. An injection delay of a selected fuel injector of the predetermined type is measured at the at least one test rail pressure. The injection delay of the selected fuel injector is estimated based on the baseline injection delay curve and the measured injection delay of the selected fuel injector at the identified test rail pressure.

Abstract: Methods and apparatus for accurately predicting a fuel injector tip temperature (FITT) are described. One technique for predicting the temperature of a fuel injector tip in an engine suitably includes the steps of estimating an initial temperature of the fuel injector tip and calculating a steady state temperature of the fuel injector tip. A filter coefficient is determined as a function of a rate of airflow into the engine, and the temperature of the fuel injector tip is predicted as a function of said initial temperature, the steady state temperature, and the filter coefficient. In a further embodiment, the steady state temperature is filtered into a feedback temperature at a rate that is determined by the filter coefficient.

Abstract: The invention intends to downsize a general-purpose engine generator and make operability thereof easy. A backup battery (233) is provided for the generator (22). The battery supplies electricity to an electronic controlled device such as a fuel pump for starting the engine. When the engine (1) carries out a rating operation, electricity is supplied from the generator (22). When the engine speed in a low speed range, only a pump (15) is driven. When the engine speed is exceeds the low speed range, the pump (15) is stopped, and an injectors, (10) and (27) are driven to be prevented from lapping over each other. When the engine speed reaches a high-speed range, the pump (15) is again driven. Electricity consumption at a time of starting is restricted by driving the electronic controlled devices at different timings until the engine (1) operation becomes self-sustaining.

Abstract: A method of calculating the voltage setpoint of a piezoelectric element as a function of a rail pressure is provided, in which a corrected voltage setpoint is formed by, among other adjustments, using a multiplier as a function of a temperature of the piezoelectric element. Additional adjustments for forming the corrected voltage setpoint includes adjusting the setpoint control voltage by multiplication by at least one correction value (multiplier) and/or by addition of at least one correction value (addend).

Abstract: A method of triggering a piezoelectric actuator which controls the injection of fuel into the combustion chamber of an internal combustion engine via a valve is described in which the operating situation of the engine is determined and the derivative with respect to time of the voltage, which can be picked off at the piezoelectric actuator, is selected as a function of the operating situation. Furthermore, a control unit for controlling a fuel injection system is described, in which a piezoelectric element is triggered so that the derivative with respect to time of the voltage, which can be picked off at the piezoelectric actuator, is adjusted to the operating situation of the engine. Additionally described is a fuel injection system, having at least one piezoelectric actuator which is triggered accordingly.

Abstract: A fuel injection control system and method for trimming an internal combustion engine during a fuel injection event based upon engine operating conditions, the control system including an electronic controller in electrical communication with the engine, the controller being operable to detect the operating mode of each injector of the engine and alter each injector operating mode as desired.

Abstract: In a method for operating an internal combustion engine (10), the fuel is supplied via at least one injection valve (32). The injected fuel quantity is influenced by the injection duration (ti). To reduce costs for the design and acquisition of the injection valve (32), it is proposed to detect as to whether a requested injection duration (ti) of the injection valve (32) is greater than a maximum possible injection duration (timxth). In this case, an intervention (64) takes place with which a desired mixture composition (rlmaxti) is produced.

Abstract: An apparatus for and method of providing improved engine performance during a change in engine load conditions reduces or eliminates engine stumbling or hesitation and/or reduces emissions levels. When an engine load change is detected (201), a compensation factor for fuel injection timing is determined (205) and combined with a base timing for fuel injection, thereby altering fuel injector timing during the transition period.

Abstract: There is provided a control system for an internal combustion engine, which is capable of matching an output torque of the engine with a demanded torque excellently when the combustion mode is switched, thereby enhancing drivability. A demanded fuel amount and a demanded torque of the engine are calculated according to detected operating conditions of the engine. A combustion mode is determined to be either the stratified combustion mode or the homogeneous combustion mode according to the demanded torque. A pre-switching demanded fuel injection time period and a pre-switching demanded torque are stored. When the combustion mode is switched, a switching-time demanded fuel amount (limit value) is calculated according to the stored pre-switching demanded fuel injection time period and pre-switching demanded torque, the current demanded torque, and an estimated combustion efficiency parameter.

Abstract: A converter mounting comprises a memory coil inductance (8), a memory primary capacitor (3) mounted upstream of said coil inductance, and a memory secondary capacitor (4), in particular, a piezoelectric actuator, mounted downstream of said coil inductance. Through control of a primary circuit element (12) and of a secondary circuit element (14), the energy of the memory primary capacitor (3) can be transferred to the memory secondary capacitor (4) and recovered.

Abstract: In an internal combustion engine in which fuel injection valves are arranged upstream from and downstream from the throttle valve, respectively, the response of the accelerated increase in quantity and correction will be improved. The total injection quantity determination unit determines a total quantity of fuel to be injected from each fuel injection valve. The injection rate determination unit determines an injection rate of the upstream injection valve. The injection quantity correction unit includes an accelerated increase in quantity and correction unit, and during acceleration, increases and corrects only the injection quantity of the downstream injection valve during acceleration.

Abstract: The force exerted on an injector valve (4, 5), by the piezo-actuator (3) on a main injection, is determined by means of a non-linear actuator model (8) and thus the gradient (?dFHdt) of the drop-off in force after the force maximum (FHmax) and a threshold value (G) are derived, with which a gradient (?dFV/dt) determined for the pre- or post-injection is compared and, depending on the result of the comparison, the signal parameter (p) for the subsequent pre- or post-injection(s) is corrected.

Abstract: An apparatus and method for improving the transient response of a spark-ignited fuel-injected internal combustion engine is disclosed. This is accomplished by employing one or more novel capillary fuel injectors. These devices are port fuel injectors modified by inserting one or more relatively small diameter heated tubular capillaries between the fuel line and a conventional injector. Sufficient heating can be produced so that flash vaporization occurs as the fuel exits the injector. The heaters are turned on using control algorithms that can be based on exhaust gas oxygen concentration, load on the engine, and accelerator pedal position.

Abstract: A method and a device for controlling the drive unit of a vehicle. In this context, at least one correction variable of the drive unit is set as a function of a setpoint value for an output variable of the drive unit, and as a function of a setpoint correction time, which represents the time in which the setpoint value for the output variable must be attained.

Abstract: A liquid fuel injection system includes an injection unit for atomizing liquid through application to the fuel vibration energy induced by the operation of piezoelectric/electrostrictive elements, and a discharge valve for discharging pressurized fuel into the injection unit. Only during a period of time when an intake valve of an internal combustion engine is closed, an electric controller supplies a drive voltage signal of a certain frequency to the piezoelectric/electrostrictive elements of the injection unit so as to operate the piezoelectric/electrostrictive elements, and a valve-opening drive signal to the discharge valve so as to discharge fuel into the injection unit from a fuel path of the discharge valve.

Abstract: A controller for an internal combustion engine capable of performing a compression ignition operation. The internal combustion engine includes a combustion chamber, and a fuel injector for injecting fuel directly in the combustion chamber. The controller includes: an air pressure detecting unit configured to detect at least one of an air pressure and an exhaust air pressure; and a fuel injection control unit configured to actuate the fuel injector to control a fuel injection timing according to a detected result by the air pressure detecting unit. The fuel injection control unit puts the fuel injection timing forward as the detected result by the air pressure detecting unit is lowered.

Abstract: In a fuel injection system for an internal combustion engine in which fuel injectors are arranged on the upstream side and on the downstream side of the throttle valve, respectively, the throttle valve will be prevented from freezing without involving the addition of piping and the like. A fuel injection system for an internal combustion engine includes a device for determining a total injection quantity of each fuel injector, a device for determining a rate of fuel injection for each fuel injector, a device for acquiring temperature information representing the throttle valve temperature, and a device for correcting the fuel injection rate on the basis of the temperature information. The correction device decreases the injection rate of the upstream fuel injector when the throttle valve is at a low temperature.

Abstract: A method of controlling fuel injection is disclosed which enables highly accurate fuel injection and an enhanced durability of fuel injection valves in an internal combustion engine using an SPI system. The engine has a plurality of fuel injection valves disposed in an intake passage on an upstream side of a collector portion of an intake manifold of the internal combustion engine so that fuel is supplied to a plurality of cylinders of the engine by fuel injection from the fuel injection valves. The method includes alternately operating the plurality of fuel injection valves so as to supply the fuel when an intake airflow is a low flow rate equal to or less than a predetermined value, and simultaneously operating the plurality of fuel injection valves so as to supply the fuel when the intake airflow is a high flow rate more than the predetermined value.

Abstract: Method for operating an internal combustion engine in which fuel is injected into a combustion chamber by an injector. The injector has a drivable piezo-actuator. A setpoint value is generated for driving the piezo-actuator. A setpoint charge quantity (QCsetpoint) is determined from the setpoint value, and an actual charge quantity (QCactual) supplied to the piezo-actuator is determined. The setpoint charge quantity (QCsetpoint) and the actual charge quantity (QCactual) are combined, and the combined result (Son) acts upon the drive circuit of the piezo-actuator.

Abstract: A fuel injection amount control apparatus estimates an intake air amount for a present or coming suction stroke of a cylinder based on an estimated throttle opening, and calculates a pre-correction estimated necessary fuel amount based on the intake air amount. The apparatus also calculates an actual intake air amount based on an actual throttle opening at the end of the previous suction stroke, and calculates an actual necessary fuel amount based on the actual intake air amount.

Abstract: A totally closed value of the throttle valve of an engine having a fast idle function will be rendered capable of being correctly detected. The opening indicated value IACV to be supplied to the motor during a fast idle operation is a value obtained by adding the water temperature correction value and the atmospheric pressure correction value to the totally closed reference value. A value obtained by subtracting the water temperature correction value and the atmospheric pressure correction value from the actual opening to be detected by the throttle sensor is set to the totally closed value. When the value obtained by subtracting the water temperature correction value and the atmospheric pressure correction value from the actual opening goes out of the dead zone, the totally closed value is replaced with the value obtained by subtracting both correction values from the actual opening.