JPH05214982A - Starting fuel control method for multi-cylinder internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce the HC constituent in the exhaust discharged when an engine is started. CONSTITUTION:Fuel is fed to individual cylinders in sequence from fuel injection valves provided on the cylinders based on the detection signals from a crank position detecting means 21 detecting the signals correspdnding to the specific crank positions of the cylinders of a multi-cylinder internal combustion engine, and no fuel is injected until a specific cylinder is identified by a cylinder identifying means 22 detecting that the specific cylinder is located at the specific crank position after the internal combustion engine is started. When the specific cylinder is identified by the cylinder identifying means 22, fuel is fed in sequence starting from the leading cylinder to be fed with fuel at this time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting fuel control method for a multi-cylinder internal combustion engine (hereinafter "internal combustion engine" may be referred to as "engine").

[0002]

2. Description of the Related Art Conventionally, a multi-cylinder internal combustion engine is provided for each cylinder based on a detection signal from a crank position detecting means (crank sensor) for detecting a signal corresponding to a specific crank position of each cylinder. A sequential fuel injection method is used in which fuel is sequentially supplied from a fuel injection valve (injector) to each cylinder. However, this sequential fuel injection method allows fuel to be supplied to each cylinder at an optimal timing, while identifying the cylinder. There is a need to.

In this case, if only one cylinder (specific cylinder) is identified, the ignition order of the cylinders is determined, so that the other cylinders can also be identified. By the way, when the engine is started, the specific cylinder cannot be identified immediately. Therefore, fuel is simultaneously injected into all the cylinders until the specific cylinder is identified (see section a in FIG. 7), and then the specific cylinder is selected. If identified, the fuel at the time of starting is sequentially supplied to each cylinder (see section b in FIG. 7), and when the engine speed exceeds a predetermined value (for example, about 200 to 300 rpm) at this time, the fuel is immediately switched to the normal fuel. (See section c in FIG. 7).

[0004]

However, in the conventional starting fuel control method for a multi-cylinder internal combustion engine as described above,
Fuel is injected into all cylinders at the same time until a specific cylinder is identified, so that unnecessary fuel may blow through the exhaust system as it is, which causes HC (hydrocarbon) in the exhaust gas.
The ingredients increase.

Further, when the specific cylinder is identified, the fuel at the time of starting is sequentially supplied to each cylinder, and when the engine speed exceeds a predetermined value in the middle, the fuel is immediately switched to the normal fuel. In some cylinders, fuel may not be supplied even once at the start, which may cause misfire due to insufficient supply of fuel in that cylinder, and as a result, the HC component also increases in the exhaust gas.

That is, the conventional starting fuel control method for a multi-cylinder internal combustion engine has a problem that the HC component increases in the exhaust gas. The present invention was devised in view of such problems, and an object thereof is to provide a starting fuel control method for a multi-cylinder internal combustion engine, which is capable of reducing HC components in exhaust gas discharged at the time of engine start. To do.

[0007]

Therefore, a starting fuel control method for a multi-cylinder internal combustion engine according to the present invention (claim 1) is a crank for detecting a signal corresponding to a specific crank position of each cylinder of the multi-cylinder internal combustion engine. The following steps are taken in the case where fuel can be sequentially supplied to each cylinder from the fuel injection valve provided for each cylinder based on the detection signal from the position detection means. (1) By the cylinder identifying means for detecting that the specific cylinder is at the specific crank position after the internal combustion engine is started,
Fuel injection is not performed until the specific cylinder is identified. (2) When the specific cylinder is identified by the cylinder identifying means, fuel is sequentially supplied from the leading fuel supply cylinder at which fuel should be injected at this time.

The starting fuel control method for a multi-cylinder internal combustion engine according to the present invention (claim 2) is a detection signal from crank position detecting means for detecting a signal corresponding to a specific crank position of each cylinder of the multi-cylinder internal combustion engine. On the basis of the above, a fuel injection valve provided for each cylinder can sequentially supply fuel to each cylinder, and the following steps are taken. (1) By the cylinder identifying means for detecting that the specific cylinder is at the specific crank position after the internal combustion engine is started,
Fuel injection is not performed until the specific cylinder is identified. (2) When the specific cylinder is identified by the cylinder identifying means, starting fuel is sequentially supplied to all the cylinders at least once starting from the leading fuel supply cylinder where fuel injection should be performed at this time.

Further, according to the starting fuel control method for a multi-cylinder internal combustion engine of the present invention (claim 3), a detection signal from crank position detecting means for detecting a signal corresponding to a specific crank position of each cylinder of the multi-cylinder internal combustion engine. On the basis of the above, a fuel injection valve provided for each cylinder can sequentially supply fuel to each cylinder, and the following steps are taken. (1) By the cylinder identifying means for detecting that the specific cylinder is at the specific crank position after the internal combustion engine is started,
Fuel injection is not performed until the specific cylinder is identified. (2) When the specific cylinder is identified by the cylinder identifying means, fuel is sequentially supplied from the leading fuel supply cylinder to which fuel injection is to be performed at this time, and during this period,
Even if the complete explosion determination means determines that the complete explosion has occurred, at least 1 is set for all cylinders starting from the leading fuel supply cylinder.
The fuel is sequentially supplied at the start.

[0010]

In the starting fuel control method for a multi-cylinder internal combustion engine according to the present invention (claim 1), the fuel injection valve provided for each cylinder is changed from the fuel injection valve provided for each cylinder to each cylinder based on the detection signal from the crank position detecting means. Fuel is sequentially supplied, but fuel injection is not performed until the specific cylinder is identified by the cylinder identifying means after the internal combustion engine is started, and the specific cylinder is identified by the cylinder identifying means. Fuel is sequentially supplied from the leading fuel supply cylinder where fuel injection should be performed.

Further, according to the starting fuel control method for a multi-cylinder internal combustion engine of the present invention (claim 2), the fuel injection valve provided for each cylinder is connected to each cylinder based on the detection signal from the crank position detecting means. Fuel is sequentially supplied, but fuel injection is not performed until the specific cylinder is identified by the cylinder identifying means after the internal combustion engine is started, and the specific cylinder is identified by the cylinder identifying means. Starting fuel is supplied to all the cylinders starting from the leading fuel supply cylinder where fuel injection is to be performed, at least once.

Further, according to the starting fuel control method for a multi-cylinder internal combustion engine of the present invention (claim 3), based on the detection signal from the crank position detecting means, the fuel injection valve provided for each cylinder is connected to each cylinder. Fuel is sequentially supplied, but fuel injection is not performed until the specific cylinder is identified by the cylinder identifying means after the internal combustion engine is started, and the specific cylinder is identified by the cylinder identifying means. While the fuel is sequentially supplied from the leading fuel supply cylinder where fuel injection should be performed, during this period, even if the complete explosion is determined by the complete explosion determination means, all the cylinders starting from the leading fuel supply cylinder are supplied. At least once, fuel is sequentially supplied at the time of starting.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 6 show a starting fuel control method for a multi-cylinder internal combustion engine as one embodiment of the present invention, and FIG. FIG. 2 is a block diagram showing a control system, FIG. 2 is a hardware block diagram of the control system, FIG. 3 is an overall configuration diagram of an engine system in which the present method is implemented, and FIGS. 4 and 5 are flowcharts for explaining the control procedure, respectively. 6 is an explanatory view of the operation.

The engine system in which the present method is carried out is as shown in FIG. 3, in which the engine (internal combustion engine) EG is connected to the intake passage 2 communicating with the combustion chamber 1.
And an exhaust passage 3, and an intake passage 2 and a combustion chamber 1
Are controlled by an intake valve 4, and the exhaust passage 3 and the combustion chamber 1 are controlled by an exhaust valve 5.

Further, the intake passage 2 is provided with an air cleaner 6, a throttle valve 7 and an electromagnetic fuel injection valve (injector) 8 in order from the upstream side, and in the exhaust passage 3, exhaust gas purification is performed in order from the upstream side. There is provided a catalytic converter (three-way catalyst) 9 and a muffler (silencer) not shown. The intake passage 2 has a surge tank 2
a is provided.

Further, the injectors 8 are provided in the intake manifold portion by the number of cylinders. Now, assuming that the engine EG of this embodiment is an in-line four-cylinder engine, four injectors 8 are provided. That is, it can be said that the engine is a so-called multi-point fuel injection (MPI) type multi-cylinder engine. Also, the throttle valve 7
Is connected to the accelerator pedal via a wire cable, so that the opening can be changed according to the amount of depression of the accelerator pedal, but it can also be opened / closed by an idle speed control motor (ISC motor). As a result, the opening of the throttle valve 7 can be changed without pressing the accelerator pedal during idling.

With such a configuration, the air sucked through the air cleaner 6 according to the opening degree of the throttle valve 7 is mixed with the fuel from the injector 8 in the intake manifold portion so as to have an appropriate air-fuel ratio, and the inside of the combustion chamber 1 is mixed. After the ignition plug is ignited at an appropriate timing to be burned to generate engine torque, the air-fuel mixture is discharged as exhaust gas to the exhaust passage 3, and the catalytic converter 9 discharges CO, HC, After the three harmful components of NOx are purified, they are silenced by the muffler and released to the atmosphere side.

Further, various sensors are provided to control the engine EG. First, on the intake passage 2 side, an air flow sensor 11 for detecting the intake air amount from the Karman vortex information, an intake temperature sensor 12 for detecting the intake air temperature, and an atmospheric pressure sensor 13 for detecting the atmospheric pressure are provided in the portion where the air cleaner is provided. The throttle valve is provided with a potentiometer-type throttle sensor 14 for detecting the opening of the throttle valve 7, an idle switch 15 for detecting an idling state, and the like.

On the exhaust passage 3 side, an oxygen concentration sensor (air-fuel ratio sensor) 17 (hereinafter, referred to as an air-fuel ratio sensor) for detecting the oxygen concentration (O ₂ concentration) in the exhaust gas is provided at an upstream side portion of the catalytic converter 9.
An O ₂ sensor 17) is provided. In addition,
As the O ₂ sensor 17, a sensor with a heater or a sensor without a heater may be used. further,
As other sensors, a water temperature sensor 19 for detecting the engine cooling water temperature, and a crank angle sensor 21 as crank position detecting means for detecting a crank angle from a signal corresponding to a specific crank position of each cylinder as shown in FIG. The crank angle sensor 21 also functions as a rotation speed sensor that detects the engine rotation speed) and a TDC sensor (cylinder discrimination) that detects that the first cylinder (specific cylinder or reference cylinder) is at top dead center (specific crank position). A sensor; cylinder identification means) 22 is provided in each distributor. The crank angle sensor 21 and the TDC sensor 2
2 is configured such that the slit plate 100 is sandwiched between a light emitting element and a light receiving element. Four slits for the crank angle sensor of the slit plate 100 are formed at 90 ° intervals, and the slits for the TDC sensor of the slit plate 100 are 180 °
Two large and small are formed at intervals (see FIG. 2).

The detection signals from these sensors are input to the electronic control unit (ECU) 23. A voltage signal from the battery sensor 25 that detects the voltage of the battery 24 and a signal from the cranking switch 26 or the vehicle speed sensor 20 that detects the start time are input to the ECU 23.

By the way, the hardware configuration of the ECU 23 is as shown in FIG. 2. The ECU 23 has a CPU 27 as its main part, and the CPU 27 has an intake air temperature sensor 12, an atmospheric pressure sensor 13, and a throttle sensor. 14, the detection signals from the O ₂ sensor 17, the water temperature sensor 19, and the battery sensor 25 are input via the input interface 28 and the A / D converter 30, and the idle switch 15, the cranking switch 26, and the vehicle speed sensor 20. The detection signal is input via the input interface 29. Also,
Air flow sensor 11, crank angle sensor 21, TDC
The detection signal from the sensor 22 is directly input to the input port of the CPU 27.

Further, the CPU 27 is a ROM for storing program data and fixed value data via a bus line.
31. While the RAM 32, which is updated and sequentially rewritten, and the battery 24 are connected, the stored contents are held so that data is exchanged with the battery backup RAM 33 backed up.

The data in the RAM 32 are erased and reset when the ignition switch is turned off. Further, the fuel injection control signal based on the calculation result in the CPU 27 is output to the four injectors 8 (more accurately, transistors for injector solenoids) via the injection driver 34.

Now, paying attention to fuel injection control (air-fuel ratio control), the CPU 27 outputs a fuel injection control signal calculated by a method to be described later to the injector solenoid via the driver 34 so that the four injectors 8 are sequentially operated. Although so Yuku so driven, for such a fuel injection control (injector drive time control), ECU 23, as shown in FIG. 1, first, to determine the basic drive time T _B for the injector 8 basic The driving time determining means 51 has a basic driving time determining means 51. The basic driving time determining means 51 includes the intake air amount A information from the air flow sensor 11 and the crank angle sensor 21.
The intake air amount A / N information per one engine revolution is obtained from the engine speed N information from the above, and the basic drive time T _B is determined based on this information.

Further, as a result of comparison between the output of the O ₂ sensor 17 and the judgment voltage (reference voltage), the engine speed N and the engine load A / N, the engine cooling water temperature detected by the water temperature sensor 19, and the intake air temperature sensor 12 are detected. There is provided a correction means 52 for setting a correction coefficient K according to the detected intake air temperature, the atmospheric pressure detected by the atmospheric pressure sensor 13 and the like, and further, the dead time for correcting the driving time according to the battery voltage. Dead time correction means 53 for setting (invalid time) T _D
Is also provided.

Therefore, the normal fuel injection time T _B × K + T _D (= T _inj ) is set by the basic drive time T _B , the correction coefficient K, and the dead time T _D. Further, a startup injection time setting means 54 for setting a startup fuel injection time Ts (= T _inj ) according to the engine cooling water temperature and the like is also provided.

A switching means 55 for selectively outputting the normal-time fuel injection time or the starting-time fuel injection time is provided, and further, a control means 61 for controlling the switching of the switching means 55 is also provided. There is. Here, switching control of the switching means 55 by the control means 61 will be described. That is, the control means 61 does not perform fuel injection until the TDC sensor 22 identifies the first cylinder after the engine EG is started, and the TDC sensor 22 identifies the first cylinder. At this time, starting fuel is sequentially supplied from the leading fuel supply cylinder (the cylinder in the exhaust stroke when the first cylinder is discriminated; the second cylinder) to which fuel injection should be performed, and during this time, Even if the complete explosion determination means 62 determines that the complete explosion has occurred, the starting fuel is sequentially supplied at least once to all the cylinders (the first, third, and fourth cylinders) starting from the second cylinder. After that, the switching means 55 is controlled so that the fuel is supplied to each cylinder sequentially during normal operation.

The complete explosion determining means 62 determines that the engine speed detected by the engine speed sensor 21 is a predetermined value (2
If it exceeds (00 to 300 rpm), it is determined that the explosion is complete. The fuel injection control will be described below with reference to the flowcharts shown in FIGS.

First, the main routine shown in FIG. 4 will be described. In step A1, it is determined whether or not the engine speed is equal to or greater than the start completion determination rotation speed. Then, set the flag to 0 after start
Then, in step A3, the starting fuel control is executed. After that, in step A1, when the number of revolutions for determining completion of starting is equal to or higher than the number of revolutions, it is determined that complete explosion has occurred, and in step A4,
It is determined whether or not the cranking switch 26 is in the on state. If the cranking switch 26 is still in the on state, the starter motor is in operation, so that the above steps A2 and A3 are executed. Continue startup processing.

When the cranking switch 26 is turned off, it is determined in the next step A5 whether or not the post-start flag has become 1. However, since the post-start flag is 0 at first, the step A6 is executed. , It is determined whether the counter value is 4. Here, each time the TDC sensor 22 detects that the first cylinder is in a predetermined crank phase and the crank angle sensor 21 detects the top dead center position of each cylinder, the counter value is incremented by one. I shall. A signal indicating that the crank angle sensor 21 has detected the top dead center position of each cylinder is called a TOP signal.

In this case, if the counter value is not 4, the NO route is taken in step A6 and the start-up process of steps A2 and A3 is still continued. After that, when the counter value becomes 4, this time in step A7, the post-start flag is set to 1 and further step A
At 8, normal fuel control is performed. After that, the engine speed is equal to or higher than the start completion determination speed, and the cranking switch 26 is also in the OFF state. Therefore, the YES route is taken in step A1, the NO route is taken in step A2, and further in step A5. Since the post-start flag is 1, the YES route is taken and the normal fuel control in step A8 is performed.

In the starting fuel control, fuel is supplied so that the air-fuel ratio becomes sufficiently richer than in the normal fuel control. By the way, when the engine is started, the cranking switch 26 is turned on to operate the starter motor. In this case, first, in step B1, the TDC sensor 22 identifies the first cylinder as shown in FIG. Determine whether or not. At this time, if the first cylinder is not identified yet, all the following steps are jumped and the return processing is performed. As a result, fuel injection is not performed until the first cylinder is identified (see section A in FIG. 6). Therefore, as compared with the conventional means in which fuel is simultaneously injected into all the cylinders until a specific cylinder such as the first cylinder is identified, unnecessary fuel is not blown through the exhaust system as it is, and as a result, HC is exhausted into the exhaust gas. It is possible to prevent the components from increasing.

Thereafter, the TDC sensor 22 causes the first
When the cylinder is identified, it is determined in step B2 whether or not the TOP signal is input. If the TOP signal is detected, in step B3, the counter value (described above) for counting the input number of the TOP signal is 4 If it is determined that the counter value is not 4, the counter value is incremented by 1 in step B5. If the counter value is 4, the counter value is cleared to 0 in step B4, and then the counter value increment process in step B5 is performed.

If the counter value after the increment is 1, the YES route is taken in step B6 to supply the starting fuel to the second cylinder (step B7). If the counter value after the increment is 2, In step B8, the YES route is taken to supply the starting fuel to the first cylinder (step B9), and the counter value after the increment is 3
In the case of step B10, the YES route is taken in step B10 to supply the starting fuel to the third cylinder (step B11), and in the case where the incremented counter value is 4, step B1
In step 2, the YES route is taken to supply the starting fuel to the fourth cylinder (step B13).

As a result, by the TDC sensor 22,
When the first cylinder is identified, fuel is sequentially supplied from the first fuel supply cylinder (second cylinder) at which fuel should be injected at this time. Then, during this period, even if the complete explosion is determined, by the processing from step A6 to step A2, A3 in FIG. 4, the starting fuel is at least once for all the cylinders starting from the second cylinder. They are sequentially supplied (see section B in FIG. 6). As a result, when a specific cylinder such as the first cylinder is identified, fuel at startup is sequentially supplied to each cylinder, and when the engine speed exceeds a predetermined value in the middle, the conventional fuel is immediately switched to. Compared to the means, in some cylinders, the fuel is not supplied even at the start even once, so there is no possibility of causing a misfire due to insufficient supply of fuel in that cylinder, and as a result, HC components still remain in the exhaust gas. It is possible to prevent the increase.

Even if the complete explosion is determined as described above, starting fuel is sequentially supplied to all the cylinders (first, third, and fourth cylinders) at least once starting from the second cylinder. After that, switching to the normal fuel is performed (see section C in FIG. 6). In addition, in the above embodiment, even if the complete explosion is determined, the starting fuel is sequentially supplied to all the cylinders (the first, third, and fourth cylinders) two or more times a predetermined number of times. Then, the fuel may be switched to the normal time.

Further, in the above embodiment, when the first cylinder is identified by the TDC sensor 22 regardless of whether or not the complete explosion is determined, the leading fuel supply cylinder (second cylinder) at which fuel injection should be performed at this time ), Starting fuel is sequentially supplied to all cylinders (first, third, and fourth cylinders) at least once (including a predetermined number of times of two times or more), and then switching to normal fuel is performed. Good.

Needless to say, the present invention can be applied not only to a 4-cylinder engine but also to a multi-cylinder engine having an arbitrary number of cylinders.

[0039]

As described above in detail, according to the starting fuel control method for a multi-cylinder internal combustion engine of the present invention (claim 1), a signal corresponding to a specific crank position of each cylinder of the multi-cylinder internal combustion engine is detected. Based on the detection signal from the crank position detecting means, the fuel can be sequentially supplied to each cylinder from the fuel injection valve provided for each cylinder. Fuel injection is not performed until the specific cylinder is identified by the cylinder identifying means that detects the position, and the cylinder identifying means
When the specific cylinder is identified, fuel is sequentially supplied from the leading fuel supply cylinder to which fuel injection is to be performed at this time. Therefore, until the specific cylinder is identified, fuel is simultaneously injected into all cylinders. Compared with the above, unnecessary fuel does not blow through the exhaust system as it is, and as a result, it is possible to prevent the HC component from increasing in the exhaust gas.

Further, in the starting fuel control method for a multi-cylinder internal combustion engine according to the present invention, when the specific cylinder is identified by the cylinder identifying means, at this time, all of the leading fuel supply cylinders from which fuel injection should be performed are started. Fuel is sequentially supplied to the cylinders at least once at startup (Claim 2), and when the specific cylinder is identified by the cylinder identifying means, at this time, fuel is sequentially injected from the leading fuel supply cylinder to be injected. While the fuel is being supplied, during this period, even if the complete explosion is determined by the complete explosion determining means, the starting fuel is sequentially supplied to all the cylinders starting from the leading fuel supply cylinder at least once. (Claim 3), when the specific cylinder is identified, the fuel at the time of starting is sequentially supplied to each cylinder, and if the engine speed exceeds a predetermined value, the fuel is immediately switched to the fuel at the normal time. Compared with the conventional means for replacing, in some cylinders, the fuel is not supplied even at the start even once, and therefore there is no fear of causing a misfire due to insufficient supply of fuel in that cylinder. There is an advantage that the HC component can be prevented from increasing.

[Brief description of drawings]

FIG. 1 is a block diagram showing a control system of a starting fuel control method for a multi-cylinder internal combustion engine as an embodiment of the present invention.

FIG. 2 is a hardware block diagram showing a control system of a starting fuel control method for a multi-cylinder internal combustion engine as an embodiment of the present invention.

FIG. 3 is an overall configuration diagram of an engine system in which the present method is implemented.

FIG. 4 is a flowchart illustrating a control procedure according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating a control procedure according to an embodiment of the present invention.

FIG. 6 is an explanatory view of the operation of the embodiment of the present invention.

FIG. 7 is a diagram for explaining the operation of the conventional example.

[Explanation of symbols]

1 Combustion Chamber 2 Intake Passage 2a Surge Tank 3 Exhaust Passage 4 Intake Valve 5 Exhaust Valve 6 Air Cleaner 7 Throttle Valve 8 Injector 9 Catalytic Converter 11 Air Flow Sensor 12 Intake Air Temperature Sensor 13 Atmospheric Pressure Sensor 14 Throttle Sensor 15 Idle Switch 17 O ₂ Sensor 19 Water temperature sensor 20 Vehicle speed sensor 26 Cranking switch 21 Crank angle sensor (engine speed sensor) as crank position detecting means 22 TDC sensor (cylinder identifying means) 23 Electronic control unit (ECU) 24 Battery 25 Battery sensor 27 CPU 28, 29 Input interface 30 A / D converter 31 ROM 32 RAM 33 Battery backup RAM 34 Injection driver 51 Basic drive time determining means 52 Correcting means 53 Dead time correcting hand 54 starting injection time setting means 55 the switching means 61 control means 62 complete explosion determining means

Claims (3)

[Claims] 1. A fuel injection valve provided for each cylinder in order based on a detection signal from a crank position detecting means for detecting a signal corresponding to a specific crank position of each cylinder of a multi-cylinder internal combustion engine. In the fuel supply device, fuel is not injected until the specific cylinder is identified by the cylinder identifying means for detecting that the specific cylinder is in the specific crank position after the internal combustion engine is started, When the specific cylinder is identified by the cylinder identifying means,
At this time, the starting fuel control method for a multi-cylinder internal combustion engine is characterized in that fuel is sequentially supplied from a leading fuel supply cylinder to which fuel injection should be performed. 2. Based on a detection signal from a crank position detecting means for detecting a signal corresponding to a specific crank position of each cylinder of a multi-cylinder internal combustion engine, a fuel injection valve provided for each cylinder is sequentially provided to each cylinder. In the fuel supply device, fuel is not injected until the specific cylinder is identified by the cylinder identifying means for detecting that the specific cylinder is in the specific crank position after the internal combustion engine is started, When the specific cylinder is identified by the cylinder identifying means,
At this time, the starting fuel control method for a multi-cylinder internal combustion engine is characterized in that starting fuel is sequentially supplied at least once to all cylinders starting from the leading fuel supply cylinder where fuel injection should be performed. 3. A fuel injection valve provided for each cylinder in order based on a detection signal from a crank position detecting means for detecting a signal corresponding to a specific crank position of each cylinder of a multi-cylinder internal combustion engine. In the fuel supply device, fuel is not injected until the specific cylinder is identified by the cylinder identifying means for detecting that the specific cylinder is in the specific crank position after the internal combustion engine is started, When the specific cylinder is identified by the cylinder identifying means,
At this time, fuel is sequentially supplied from the leading fuel supply cylinder to which fuel injection is to be performed, and during this period, even if the complete explosion determination means determines complete explosion, all the cylinders are started from the leading fuel supply cylinder. On the other hand, a starting fuel control method for a multi-cylinder internal combustion engine, characterized in that fuel at the time of starting is sequentially supplied at least once.