Abstract:
An engine has a fuel injection system and an idle regulating control valve. The idle regulating valve is initialized upon engine shut down by closing to a fully closed position such that a reference value can be obtained in such a position. Once fully closed, the idle regulating valve is opened to a predetermined position and a value is written into memory that indicates that the initialization procedure has been completed. During subsequent restart, if it appears that the initialization procedure has not been completed prior to attempted restart, fuel injection is temporarily suspended. The fuel injection can be suspended during a subsequent initialization, until the idle regulating valve is fully closed or for a predetermined period of time. In some less refined applications, the idle regulating valve can be initialized during engine start up regardless of whether or not it is initialized during engine shut-down.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Related Applications  
         [0002]     This application claims the priority benefit of Japanese Patent Application No. 2004-150993, filed on May 20, 2004, which is hereby incorporated by reference in its entirety.  
         [0003]     2. Field of the Invention  
         [0004]     The present invention generally relates to an engine provided with an idle regulating valve for supplying secondary air from the atmosphere to an intake pipe extending from a main engine unit. More particularly, the present invention relates to such an engine in which secondary air from the atmosphere is supplied to the intake pipe through the idle regulating valve when the engine is started.  
         [0005]     3. Description of the Related Art  
         [0006]     JP-A-Hei 11-270391 discloses an engine in which idle speed is regulated by air flow through a secondary air passage, which air flow is regulated by an idle regulating valve. The engine disclosed in the publication has a main engine unit that generates and outputs driving power. An intake pipe extends to the main engine unit and a throttle valve is positioned along the intake pipe. The throttle valve adjusts the opening of an intake passage inside the intake pipe. A fuel injection valve supplies fuel to the main engine unit. An idle regulating valve supplies secondary air from the atmosphere to the intake passage. A controller electronically controls operations of the fuel injection valve and the idle regulating valve.  
         [0007]     In the engine disclosed in the Japanese publication, when the main engine unit is stopped, the controller initializes the idle regulating valve by moving the idle regulating valve to a fully closed position. When the idle regulating valve is fully closed, a reference value for controlling the idle regulating valve is determined and then the idle regulating valve is opened to a predetermined initial opening.  
         [0008]     When the engine is operated, air from the atmosphere is supplied through the intake passage to the main engine unit. Fuel is added to the air passing through the intake pipe with the fuel injection valve. The air/fuel mixture is combusted within the engine. This generates thermal energy, which in turn causes the main engine unit to output driving power.  
         [0009]     The throttle valve is opened or closed to adjust the opening of the intake passage (throttle opening) so that a predetermined quantity of air is drawn through the intake passage and the throttle valve into the main engine unit from the atmosphere. The air flow into the engine regulates the engine-speed.  
         [0010]     When the engine is being driven, a sufficient quantity of air may not be supplied to the main engine unit under idle due to the smaller throttle opening. In this case, feedback control that is designed to achieve a target rotational speed of the engine opens the idle regulating valve. Thus, secondary air from the atmosphere is supplied through the idle regulating valve to the main engine unit in order to account for the air supply shortage. The combination of the air passing through the intake passage and the air passing through the secondary passage provides a sufficient volumetric air flow to maintain a desired idling condition.  
         [0011]     Typically, the idle regulating valve is not provided with any sensor to detect its degree of opening. Providing such a sensor would complicate the engine design. Thus, in most engines, detecting an actual opening of the idle regulating valve while the engine is operating would be impossible. As a result, when operation of the main engine unit is stopped, such as by turning a main switch to an off-position, the idle regulating valve is initialized. By initializing the valve, accurate positioning of the valve during a subsequent restart can be obtained.  
         [0012]     Currently, the idle regulating valve is initialized as soon as the main engine unit is stopped. To initialize the valve, the valve is first fully closed. Once fully closed, a reference value for position control is determined. The idle regulating valve is then opened to a predetermined initial opening position. Once in the predetermined initial opening position, secondary air is supplied to the main engine unit through the idle regulating valve during later subsequent restarts of the engine. Because the main air flow is supplemented by air passing through the idle regulating valve, sufficient air is provided to the main engine unit to encourage a smooth restart. Once the engine is operating, the position of the idle regulating valve is appropriately controlled during normal engine operation based on the reference value.  
         [0013]     In accordance with the strategy described above, it is assumed that the main engine unit is stopped by turning the main switch off while the engine is operating normally and, accordingly, the idle regulating valve will be initialized by a moving it to a fully-closed position. Unfortunately, such a sequence of events does not always take place before the engine is restarted. In other words, it is conceivable that the main engine unit can be stopped for such a brief period of time that the idle regulating valve cannot complete its initialization procedure. In such a scenario, the main engine unit is stopped and, immediately thereafter, a restart of the main engine unit is attempted. Because initializing the idle regulation valve is not completed, the first ignition cycle of air-fuel mixture would likely occur in the main engine unit while the idle regulating valve is being closed for initialization. Thus, the idle regulating valve would not be brought into its fully closed position until the initial ignition cycle had already occurred. Such a situation would block introduction of secondary air into the main engine unit and could likely result in a supply shortage of air immediately after the first explosion. The sudden decrease in air supply would result in an abrupt stop of the engine. This abrupt engine stop would require one or more subsequent attempts to restart the engine, which is undesirable.  
       SUMMARY OF THE INVENTION  
       [0014]     Accordingly, an engine is desired which can restart immediately after the main engine unit is stopped.  
         [0015]     In one arrangement, an engine comprises a main engine unit. An intake pipe is connected to the main engine unit. The intake pipe defines an intake passage. A throttle valve is positioned within the intake passage. A fuel injection valve is connected to the main engine unit. An idle regulating valve is connected to the intake passage. A controller is electrically connected to the fuel injection valve and the idle regulating valve. The controller is configured to move the idle regulating valve to a fully closed state prior to initiating fuel injection during an engine start.  
         [0016]     In another arrangement, a method of controlling an engine comprising an idle regulating valve and a fuel injection valve is provided. The method comprises performing an idle regulating valve initialization that comprises moving the idle regulating valve to a fully closed position, determining a reference value when the idle regulating valve is in the fully closed position, and opening the idle regulating valve to a predetermined position. The method further comprises storing in a memory location a value indicative of a completion of the idle regulating valve initialization and interrupting fuel injection at least until the idle regulating valve reaches its fully closed position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     These and other features, aspects and advantages of the present invention will now be described with reference to the drawings of several preferred embodiments, which embodiments are intended to illustrate and not to limit the invention. The drawings comprise 5 figures.  
         [0018]      FIG. 1  is an overall schematic diagram of an engine that is arranged and configured in accordance with certain features, aspects and advantages of a first embodiment of the present invention.  
         [0019]      FIG. 2  is a simplified sectional view of an idle regulating valve that is used in the arrangement of  FIG. 1 .  
         [0020]      FIG. 3  is a flowchart of a control system that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.  
         [0021]      FIG. 4  is a timing chart showing a normal driving condition of the engine of  FIG. 1 .  
         [0022]      FIG. 5  is a timing chart showing a different driving condition of the engine of the  FIG. 1 .  
         [0023]      FIG. 6  is a flowchart of another control system that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.  
         [0024]      FIG. 7  is a flowchart of a further control system that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]     With reference to the figures, an engine is provided with a control system and an idle regulation valve such that, upon engine shutdown, the idle regulation valve is closed and reset to a predetermined first position prior to the engine being restarted. In one configuration, the supply of fuel to the engine can be prevented until the idle regulation valve has been fully closed in a reset operation if the idle regulation valve is not fully reset prior to operation of a starter of the engine. In another configuration, the supply of fuel to the engine can be prevented for a predetermined period of time after the starter is operated if the idle regulation valve has not been reset prior to operation of the starter. In yet another configuration, the supply of fuel to the engine can be prevented until the idle regulation valve has been fully closed in a reset operation during subsequent restarting of the engine.  
         [0026]     With reference now to  FIG. 1 , reference numeral  1  denotes a four-stroke multi-cylinder engine (internal combustion engine) that can be mounted in or on a vehicle, such as the engines used in outboard motors, for instance but without limitation. The engine  1  has a main engine unit  2 . The main engine unit  2  includes: a crankcase  4  for supporting a crankshaft  3 ; a cylinder  5  protruding from the crankcase  4 ; a piston  6  fitted into the cylinder  5 ; a connecting rod  7  for operatively connecting the crankshaft  3  and the piston  6  to each other; a valve mechanism  8 ; and an ignition plug  9 .  
         [0027]     The engine  1  has an intake pipe  12  extending from the main engine unit  2  and a throttle valve  14  for adjusting the opening (throttle opening) of the intake passage  13  inside the intake pipe  12 , in which air  15  from the atmosphere flows sequentially to the throttle valve  14  and the intake passage  13  to be introduced to a combustion chamber in the main engine unit  2 .  
         [0028]     The engine  1  further has: a fuel injection valve  18  for supplying fuel  17  to the main engine unit  2  through the intake passage  13 ; a primary pump  20 , a low-pressure pump  21  and a high-pressure pump  22 , which are designed to deliver fuel  17  from a fuel tank  19  to the fuel injection valve  18 ; and a fuel filter  23  for filtering sediment and other impurities from the fuel  17 . In some configurations, the fuel injection valve  18  can be solenoid-operated. The engine can utilize direct cylinder injection in some arrangements and can use indirect or port injection in other arrangements.  
         [0029]     With reference to  FIGS. 1 and 2 , an idle regulating valve  25  is provided for supplying secondary air  24  from the atmosphere to the intake passage  13  as appropriate. The idle regulating valve  25  can be an idle speed control (ISC) valve, which has: a valve box  26  fixed to the intake pipe  12 ; a valve seat  27  formed on the valve box  26 ; a valve body  28  for opening or closing the valve seat  27 ; a spring  29  for elastically biasing the valve body  28  to a closed position; and a stepping motor  30  or an actuator for opening or closing the valve body  28 . Other suitable valve configurations also can be used. In the illustrated arrangement, driving the stepping motor  30  in a first direction as shown by the arrow (R) opens the valve body  28 , thereby opening the valve seat  27  while driving the stepping motor  30  in a reverse direction relative to the arrow (R) closes the valve body  28 , thereby contacting the valve seat  27 .  
         [0030]     A starter  32  or a starter motor is operatively connected to a crankshaft  3  of the main engine unit  2 . Actuating the starter  32  rotates the crankshaft  3  during engine starting.  
         [0031]     In the main engine unit  2 , there are provided: a crank angle detecting sensor  34  for detecting a crank angle of the crankshaft  3 ; an opening detecting sensor  35  for detecting a throttle opening of the throttle valve  14 ; and a negative-pressure detecting sensor  36  for detecting a negative-pressure in the intake passage  13 . Other suitable sensors also can be provided.  
         [0032]     An engine controller  39  is provided for electrically controlling the engine  1 . To the controller  39  are electrically connected the ignition plug  9 , the fuel injection valve  18 , the primary pump  20 , the low-pressure pump  21 , the high-pressure pump  22 , the stepping motor  30  for the idle regulating valve  25 , the starter  32  and the respective sensors  34  to  36 . A battery  40  is also connected to the controller  39  to supply power to the controller  39  via a main switch  41 . A latching circuit  42  is used in the illustrated arrangement to hold the main switch  41  in an on-position and the latching circuit includes a main relay. The controller  39  advantageously has a memory  43  for storing an indicator of the completion status of an idle regulating valve initializing control, which will be discussed later. In the illustrated arrangement, the memory  43  is made up of an EEP and a ROM. Other suitable configurations also can be used.  
         [0033]     When the engine  1  is controlled by the controller  39 , air  15  from the atmosphere is supplied through the intake passage  13  to the main engine unit  2 , to which fuel  17  is also supplied by the fuel injection valve  18  for combustion. This generates thermal energy, which is converted to mechanical energy, which causes the main engine unit  2  to output driving power.  
         [0034]     The throttle valve  14  is opened or closed to adjust the opening of the intake passage  13  (throttle opening), so that a predetermined quantity of the air  15  is drawn through the intake passage  13  and the throttle valve  14  into the main engine unit  2  from the atmosphere. This can regulate the operating condition of the engine  1 , such as high-speed operation and low-speed operation.  
         [0035]     When the engine  1  is operating, a sufficient quantity of the air  15  may not be supplied to the main engine unit  2  during idling operation due to the smaller degree of throttle opening. To compensate, the controller  39  uses feedback control that is designed to achieve a target rotational speed of the engine  1  by opening and closing the idle regulating valve  25 , as appropriate. Thus, secondary air  24  from the atmosphere is supplied through the idle regulating valve  25  to the main engine unit  2  in order to make up for a supply shortage of the air flowing past through the throttle opening. This maintains a suitable idling condition.  
         [0036]     In the illustrated arrangement, the idle regulating valve  25  is not provided with an opening-detecting sensor in order to simplify the physical construction of the engine  1 . Thus, when the main engine unit  2  is stopped by turning the main switch  41  off, an initializing control is implemented, such that appropriate control for operating the idle regulating valve  25  to open or close is possible while the engine is otherwise operating after the restart of the main engine unit  2 .  
         [0037]     When the main engine unit  2  is stopped, the initializing control first closes the idle regulating valve  25  until it is fully closed, under which state a reference value for the initializing control is determined. The idle regulating valve  25  is then opened to a predetermined initial opening. After the initial opening is achieved, secondary air  24  is supplied to the main engine unit  2  through the idle regulating valve  25  at the restart of the engine  1 . This encourages a smooth restart of the engine. Accordingly, completion of the initializing control requires positioning the idle regulating valve  25  in the predetermined initial opening. Upon restart of the engine, the idle regulating valve can be appropriately controlled based on any suitable control strategy (e.g., a reference value depending upon the operating parameters of the engine  1 ) which, in some embodiments, can be operated relative to the reference value generated during the initializing control.  
         [0038]     With reference now to  FIGS. 3-5 , a control routine will be described that can be used to provide complete initialization of the idle regulating valve before combustion begins. With reference initially to  FIG. 3 , a flowchart of one control process for the controller  39  is illustrated in which symbol S denotes each step of the program.  FIG. 4  provides a time chart that reflects a relatively normal operating condition of the engine  1 .  FIG. 5  provides a comparable time chart in which the engine  1  is rapidly restarted following shutdown. In  FIG. 5 , detailed descriptions of common parts and components with the same reference numeral as those shown in  FIG. 4  are not repeated.  
         [0039]     With reference to arrangement illustrated in  FIGS. 3 and 4 , when the main switch  41  is turned on (S 1  in  FIG. 3  and occurring at time (a) in  FIG. 4 ), the power supply voltage of the controller  39  increases from zero V to 12V through the battery  40 , so that the controller  39  powers-up (S 2  in  FIG. 3 ). Then, a determination is made whether or not there is something abnormal in the contents stored in the memory  43  or something different from the intended contents (S 3  in  FIG. 3 ). To be more specific, a value, other than the value to be stored in the ROM when the previous initializing control has been completed, corresponds to “abnormal.” On the other hand, a value equal to the value to be stored in the ROM when the aforementioned initializing control has been completed is determined not “abnormal” but normal. The value to be stored in the ROM when the initializing control has been completed refers to a value which indicates that the idle regulating valve  25  is in the initial opening state (ISC opening at (a) in  FIG. 4 ). For instance, a flag can be used to indicate when the idle regulating valve has moved from a fully closed position to the predetermined initial opening. The flag value might increment or decrement upon each restart such that a distinction between a prior initialization and an expected current initialization can be maintained. In other arrangements, such as that illustrated, the value stored in memory is erased or written to zero once the idle regulating valve begins being controlled during normal engine operation.  
         [0040]     At S 3  in  FIG. 3 , it is assumed that the contents stored in the memory  43  would be determined not abnormal but normal. If such a determination is made, the starter  32  is activated ((b) to (c) in  FIG. 4 ) and the fuel injection valve  18  injects fuel  17  (S 4  in  FIG. 3 ) for supply to the main engine unit  2 . Activating the main engine unit  2  allows the engine  1  to start ((b) to (C) in  FIG. 4 ).  
         [0041]     As described above, the engine  1  is a multi-cylinder engine. Thus, at the start of the engine  1 , a single pulser coil can be used to determine the operational state (e.g., compression, expansion, ignition, etc.) of each cylinder. Next, based on the signals detected by the pulser coil, the fuel injection valve  18  causes the fuel  17  to be supplied sequentially to each cylinder. In this case, however, figuring out which stroke each cylinder is on causes a delay in supplying the fuel  17 . Therefore, it would possibly take longer to start the engine  1  after cranking by activating the starter  32 . Therefore, in one embodiment, the fuel  17  is pre-injected by each fuel injection valve  18  while the operational state of each cylinder is detected, such as by the pulser coil. This can reduce the time between cranking and starting of the engine  1 .  
         [0042]     In the above-described situation, after the controller  39  starts-up with the operation of the main switch  41 , the environmental conditions, such as a cold climate, can be initially detected prior to figuring out which stroke each cylinder is on. Based on the detected signal, a quantity of the fuel  17  to be injected by the fuel injection valve  18  for each cylinder can be determined, as well as which fuel injection valve  18  to pre-inject. Thus, the above configuration can provide an engine start that is suitable for the environment conditions, and therefore, the engine  1  can start immediately upon cranking by the starter  32 .  
         [0043]     In contrast, if the starter  32  is activated in order to start the engine  1  as described above, the power supply voltage of the controller  39  may sharply decrease once (see time (b) in  FIG. 4 ). Such a sharp decrease in voltage could cause the controller  39  to be temporally turned off. The idle regulating valve  25  can start operating after a lapse of predetermined time ((b) to (d) in  FIG. 4 ) once the starter  32  is activated. As mentioned above, the contents stored in the memory  43  preferably are cleared at the operation start of the idle regulating valve  25 .  
         [0044]     When the engine  1  is started ((b) in  FIG. 4 ), the feedback control by the controller  39 , which is designed to achieve the target rotational speed of the engine  1 , opens the idle regulating valve  25  ((d)-(c) in  FIG. 4 ). The secondary air  24  is then supplied to the main engine unit  2  through the idle regulating valve  25  and the intake passage  13 . This greatly reduces the likelihood of a shortage of the supply of air  15 ,  24  to the main engine unit  2 , which provides a smoother start of the engine  1 . After the engine starts, normal operation of the engine  1  is maintained ((c) to (e) in  FIG. 4 ).  
         [0045]     Turning the main switch  41  off to stop engine operation (S 5  in  FIG. 3  and time (e) in  FIG. 4 ) stops injection of the fuel  17  by the fuel injection valve  18  (S 6  in  FIG. 3 ), resulting in a gradual stop of the main engine unit  2  ((e) to (f) in  FIG. 4 ). Although the main switch  41  has been turned off, the latching circuit  42  maintains the power supply voltage of the controller  39  substantially constant for a predetermined time ((f) to (g) in  FIG. 4 ). After the main engine unit  2  has stopped (S 7  in  FIG. 3 , (f) in  FIG. 4 ), the initializing control of the idle regulation valve starts and the controller  39  can properly control the idle regulating valve  25  (S 8  in  FIG. 3  and (f) in  FIG. 4 ).  
         [0046]     Under the initializing control, stopping the main engine unit  2  first causes the idle regulating valve  25  to close to the fully closed state ((h) in  FIG. 4 ). A reference value for the initializing control is determined in this fully closed state. After that, the idle regulating valve  25  is appropriately controlled relative to the reference value while the engine  1  is being operated under normal conditions.  
         [0047]     The idle regulating valve  25  is opened to a predetermined initial opening (times (h) to (i) in  FIG. 4 ). In other words, opening the idle regulating valve  25  results in a supply of the secondary air  24  to the main engine unit  2  through the idle regulating valve  25  immediately at a restart of the engine  1 . This allows a sufficient supply of the air  15 ,  24  to the entire engine main unit  2 , providing a smooth start of the engine. When the idle regulating valve  25  is positioned in the predetermined initial opening position, the initializing control is completed (S 9  in  FIG. 3  and (i) in  FIG. 4 ).  
         [0048]     Next, the completion status of the initializing control is written to the memory  43  and stored therein. More specifically, a value, which indicates that the idle regulating valve  25  has been opened to the predetermined initial opening, is written and stored in the memory  43  (S 10  in  FIG. 3 ). Then, the latching circuit  42  is automatically turned off, and therefore the controller  39  is turned off (S 11  in  FIG. 3  and (g) in  FIG. 4 ).  
         [0049]     The timing diagram of  FIG. 5  illustrates that the initialization of the idle regulating valve  25  is completed before the engine is started. As shown, when the main engine unit  2  is stopped by turning the main switch  41  off (S 5  in  FIG. 3  and timing (e) in  FIGS. 4 and 5 ), the initializing control for the idle regulating valve  25  starts (S 8  in  FIG. 3  and timing (f) in  FIGS. 4 and 5 ). If the main switch  41  then is turned on (S 1  to S 3  in  FIG. 3  and time (j) in  FIG. 5 ) and the starter  32  is turned on (time (j) in  FIG. 5 ), which is designed to restart the engine  1 , during the course of the initializing control, the fuel injection is suspended until the initializing control has completed.  
         [0050]     Then, in S 3  in  FIG. 3 , a determination is made whether or not there is something abnormal in the contents stored in the memory  43 . In this situation, since the initializing control is under way, no completion status of the initializing control is stored in the memory  43 . Thus, in S 3  in  FIG. 3 , the contents stored in the memory  43 , which are different from those intended to indicate the completion status of the initializing control, are determined to be abnormal. The idle regulating valve  25  is again subject to the initializing control (S 12 , S 13  in  FIG. 3  and (j) to (m) in  FIG. 5 ).  
         [0051]     As a process of the initializing control, first it is assumed in S 12  that the idle regulating valve  25  is in the fully opened state (100%). Next, the information of the number of operation pulses counted until the idle regulating valve  25  expectedly reaches the fully closed state (0%) is provided for the stepping motor  30  of the idle regulating valve  25 . Closing operation of the idle regulating valve  25  starts (S 12  in  FIG. 3  and (j) in  FIG. 5 ).  
         [0052]     According to the program for S 12 , the idle regulating valve  25  is assumed to continue its closing operation. However, the idle regulating valve  25  is substantially in the fully closed state ((l) in  FIG. 5 ). After that, the idle regulating valve  25  is actually maintained in the fully closed state with its closing operation stopped ((l) to (k) in  FIG. 5 ). In contrast, under the initializing control, the idle regulating valve  25 , which is assumed to be in the fully opened state, is supposed to continue its closing operation to the intended fully closed state (S 13  in  FIG. 3 , See a dotted line in (j) to (k) in  FIG. 5 ).  
         [0053]     Even if the starter  32  is maintained on (j) to (m) in  FIG. 5 ) in order to restart the engine  1 , the fuel injection valve  18  is stopped from injection until the idle regulating valve  25  becomes fully closed ((k) in  FIG. 5 ) in the program for S 12 . In other words, a supply of the fuel  17  to the main engine unit  2  by the fuel injection valve  18  is stopped unless the idle regulating valve  25  is brought in the fully closed state ((k) in  FIG. 5 ) under the initializing control, thereby preventing a first ignition from occurring in the main engine unit  2  (S 14  in  FIG. 3 ).  
         [0054]     Next, the idle regulating valve  25  is opened to the predetermined initial opening ((n) in  FIG. 5 ). In this case, the main engine unit  2  is being operated. So after that, the main engine unit  2  continues to be operated by opening or closing the throttle valve  14  and the engine  1  operates normally ((c)-(e) in  FIG. 4  and from (m) onward in  FIG. 5 ).  
         [0055]     The aforementioned configuration is provided with the memory  43  for storing the completion status of the initializing control. At the start of the engine  1 , if there is something abnormal in the contents stored in the memory  43  or different from the intended contents, the idle regulating valve  25  is subject to the initializing control, during which supply of fuel  17  by the fuel injection valve  18  is stopped unless the idle regulating valve  25  is brought in the fully closed state.  
         [0056]     When the engine  1  is restarted immediately after the main engine unit  2  is stopped, if the initializing control is under way, the memory  43  would not reflect that the initializing control has been completed. Therefore, at the restart of the engine  1 , the contents stored in the memory  43 , which are different from those intended to indicate the completion status of the initializing control, would be determined to be abnormal. Then, the idle regulating valve  25  is again subject to the initializing control, as previously mentioned.  
         [0057]     With reference now to  FIGS. 6 and 7 , two additional control routines that are arranged and configured in accordance with certain features, aspects and advantages of the present invention are illustrated therein. The components, functions and effects of these embodiments are similar in many respects to those of the first embodiment above. Thus, redundant descriptions will not be provided and identical reference numerals or symbols will be provided to the corresponding components. Thus, the following description will focus mainly upon the differences between the arrangement described above and the arrangements of  FIGS. 6 and 7 . It should be noted that certain features, aspects and advantages of each of the embodiments described herein can be integrated into others of the embodiments described herein.  
         [0058]     With reference now to  FIG. 6 , S 15  is incorporated in the routine of  FIG. 3  in place of S 13 . In S 15 , after the engine  1  is started by turning the starter  32  on at S 12  while the idle regulating valve  25 , which is assumed to be in the fully opening state, starts its closing operation, a supply of the fuel  17  by the fuel injection valve  18  is stopped until a predetermined time of period has been elapsed following cranking of the engine  1  by the starter  32 .  
         [0059]     As described above, it is assumed that the main switch  41  is turned off while the engine is operating so that the main engine unit  2  is stopped. This causes the idle regulating valve  25  to be subject to the initializing control. In this case, immediately after the main engine unit  2  is stopped, the main switch  41  and the starter  32  are both turned on in order to restart the main engine unit  2 . Therefore, unlike the conventional configuration, this prevents the engine  1  from stopping long enough prior to restart for initialization to be completed. In other words, when the engine  1  is restarted immediately after the main engine unit  2  is stopped, if the initializing control is under way, no completion status of the initializing control would be stored in the memory  43 . Therefore, at the restart of the engine  1 , the contents stored in the memory  43 , which are different from those intended to indicate the completion status of the initializing control, are determined to be abnormal. Thus, a supply of the fuel  17  to the main engine unit  2  by the fuel injection valve  18  is stopped until a predetermined time of period has been elapsed, as previously noted. That is, this prevents the first ignition from occurring in the main engine unit  2  before the idle regulating valve  25  is fully closed.  
         [0060]     With reference now to  FIG. 7 , S 3  and S 12  of the routine shown in  FIG. 3  are removed in the routine shown in  FIG. 7 . The main switch  41  is turned on (S 1 ) so that the controller  39  starts-up, which immediately leads to the implementation of the initializing control for the idle regulating valve  25  (S 13 ). A supply of the fuel  17  by the fuel injection valve  18  is stopped (S 14 ) unless the idle regulating valve  25  is fully closed under the initializing control.  
         [0061]     As described above, it is assumed that the main switch  41  is turned off while the engine is operating which leads to stoppage of the main engine unit  2 . This causes the idle regulating valve  25  to be subject to the initializing control. In this case, immediately after the main engine unit  2  is stopped, the main switch  41  and the starter  32  are both turned on in order to restart the main engine unit  2 . Therefore, unlike the conventional configuration, this prevents the engine  1  from stopping long enough prior to restarting such that initialization cannot be completed. In other words, when the engine  1  is restarted immediately after the main engine unit  2  is stopped, whether the initializing control is under way or not, the idle regulating valve  25  is again subject to the initializing control.  
         [0062]     Under the initializing control, a supply of the fuel  17  to the main engine unit  2  by the fuel injection valve  18  is stopped unless the idle regulating valve  25  is brought in the fully closed state. That is, this prevents the first ignition from occurring in the main engine unit  2  before the idle regulating valve  25  is brought in the fully closed state.  
         [0063]     Although the present invention has been described in terms of a certain embodiment, other embodiments apparent to those of ordinary skill in the art also are within the scope of this invention. Thus, various changes and modifications may be made without departing from the spirit and scope of the invention. For instance, various components may be repositioned as desired. Moreover, not all of the features, aspects and advantages are necessarily required to practice the present invention. As used herein, “abnormal” contents stored in the memory  43  includes contents that are different from any intended data stored and also includes no contents, which indicates that initialization has not been completed. In some arrangement, the main switch  41  can be a kill switch. Accordingly, the scope of the present invention is intended to be defined only by the claims that follow.