The present disclosure, in general, relates to an internal combustion engine having port fuel injection operating mode, and in particular, to a method and system for reducing emissions, reducing port wall wetting and improving fuel efficiency by splitting complete required fuel injection quantity into a plurality of fuel injections of smaller quantity keeping total fuel quantity same by maintaining achieve air-fuel ratio at stoichiometric.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention.
[0003] Generally, Internal Combustion (IC) engine can have two type of fuel injections one is direct fuel injection and other is indirect fuel injection. In the direct fuel injection mode, the fuel injectors are positioned directly into combustion chamber so that fuel can be injected into combustion chamber and air-fuel mixture is prepared in the combustion chamber itself. In the direct fuel injection mode, the fuel can be injected by fuel injectors during intake stroke/mode or compression stroke or during both intake as well as compression stroke by dividing the fuel injection into two parts.
[0004] In the indirect fuel injection mode which can be referred as port fuel injection mode where fuel injectors are positioned in air intake manifold or intake manifold. The fuel injectors inject the fuel in the air intake manifold for homogenous mixture of air and fuel to achieve better emission performance and fuel economy.
[0005] In conventional system, during the event of cold/hot Start of an engine, the Driver cranks the vehicular engine using the cranking options provided by manufacturer [i.e. by Ignition Key or switches. Etc.,]. On cranking the IC engine, the starter motor rotates the engine and the Engine Control Unit (ECU) calculates

the quantity of fuel to be injected into the engine in order to allow desired air fuel mixture into combustion chamber of the IC engine so that the engine can start and achieve self-sustaining speed. The calculated fuel quantity is converted into injection time and is injected in one complete injection in to intake manifold.
[0006] Technical Problem: the existing single injection needs appropriate time and distance for proper atomization so that fuel can be mixed with air completely, making it homogeneous mixture. To provide appropriate time for air and fuel to mix homogenously, appropriate distance is kept between injection point and engine intake valve. This increase in the distance of fuel injectors from the engine intake valve, increases the chance of intake manifold wall wetting making air fuel mixture rich and increases emissions. The existing system also decreases fuel economy as fuel become dense and make port wall wetting. In the view of the above-cited problem(s), there is a need for a method and a system that can be implemented in the existing Engine Control Unit (ECU) to maintain air-fuel ratio at stoichiometric and reduce port wall wetting in the intake manifold. Further, the system allows installation of fuel injectors close to engine intake valve for better fuel economy, avoiding port wall wetting and fuel puddle formation.
OBJECTS OF THE DISCLOSURE
[0007] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.
[0008] It is a general object of the present disclosure to provide an Engine Control Unit (ECU) to split fuel quantity into multiple fuel injections to achieve homogenous air-fuel mixture or air-fuel ratio at stoichiometric.
[0009] It is another object of the present disclosure to provide an ECU that allows positioning of fuel injectors in intake manifold close to intake valve of Internal Combustion engine.
[0010] It is another object of the present disclosure to provide a method for splitting/dividing total fuel quantity into multiple fuel injections to reduce port

wetting and improve emission performance by giving appropriate time for fuel to mix with air.
[0011] These and other objects and advantages of the present invention will be apprent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY
[0012] This summary is provided to introduce concepts related to an engine control unit having a port fuel injection mode with split fuel injection. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0013] In an embodiment, the present disclosure relates to an Engine Control Unit (ECU) for reducing emissions, reducing port wall wetting, and improving fuel economy by splitting fuel injection. The ECU comprising a fuel controller coupled with a plurality of fuel injectors positioned in an intake manifold for controlling fuel injection. The fuel controller is configured to calculate fuel quantity to be injected into the intake manifold and to calculate fuel injection time based the calculated fuel quantity. The fuel controller further divides the fuel injection time and the fuel quantity into a plurality of fuel injections to allow fuel to mix with air completely and maintaining air-fuel ratio at stoichiometric.
[0014] In an embodiment, the fuel controller is coupled with an Engine Control Unit to calculate fuel quantity to be injected into the intake manifold based on feedback signal received from Lambda sensor.
[0015] In an embodiment, the plurality of fuel injections is made in the intake manifold during exhaust stroke of the previous cycle of an engine.
[0016] In an embodiment, the fuel controller determines time between two
consecutive fuel injections from the plurality of fuel injections by measuring time

required for fuel to flow from Point of Injection (POI) to Point of Optimum Sauter Mean Diameter (SMD) of each of the fuel injector from the plurality of fuel injectors.
[0017] In an embodiment, an injected fuel quantity by first fuel injection
homogeneously mixes with air in the Intake Manifold before second fuel injection during single exhaust stroke.
[0018] In an embodiment, the fuel controller determines number of fuel injections in single exhaust stroke of the previous cycle in an IC engine to maintain Air-fuel ratio at stoichiometric.
[0019] In an embodiment, number of fuel injections in the plurality of fuel injections is selected from two or three or more to maintain air-fuel ratio at stoichiometric in the intake manifold to reduce emissions, port wall wetting, and to improve fuel efficiency.
[0020] In another embodiment, the present subject matter relates to a method for reducing emissions, port wall wetting, and improving fuel economy of an internal combustion (IC) engine having a port fuel injection mode where a plurality of fuel injectors is positioned in an Intake Manifold. The method comprising calculating fuel quantity to be injected into the intake manifold; calculating fuel injection time based the calculated fuel quantity; and dividing the fuel injection time and the fuel quantity into a plurality of fuel injections to maintain air-fuel mixture to stoichiometric.
[0021] In an embodiment, the method includes calculating fuel quantity to be injected into the intake manifold based on feedback signal received from Lambda sensor to maintain air-fuel ratio at stoichiometric to reduce emissions.
[0022] In an embodiment, the method includes injecting the plurality of fuel injections into the intake manifold during exhaust stroke of the previous cycle in the IC engine.
[0023] In an embodiment, the method includes determining time difference between two consecutive fuel injections from the plurality of fuel injections by

measuring time required for fuel to flow from Point of Injection (POI) to Point of Optimum Sauter Mean Diameter (SMD) of each of the fuel injector from the plurality of fuel injectors.
[0024] In an embodiment, the method includes determining number of fuel injections in single exhaust stroke of the previous cycle in the IC engine to maintain Air-fuel ratio at stoichiometric.
[0025] In an embodiment, the method includes selecting number of fuel injections in the plurality of fuel injections from two or three or more to maintain air-fuel ratio at stoichiometric in the intake manifold to reduce emissions, port wall wetting, and to improve fuel efficiency.
[0026] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
[0027] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[0028] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in

accordance with embodiments of the present subject matter are now described, by way of example only, and with reference to the accompanying figures, in which:
[0030] Fig. 1 illustrates architecture of Internal Combustion Engine with fuel Injectors and Engine Control Unit;
[0031] Fig. 2 illustrates a system architect of the Engine Control Unit (ECU) coupled with plurality of fuel injectors, lambda sensor, coolant sensor and engine speed sensors, in accordance with an embodiment of the present disclosure;
[0032] Fig. 3a illustrates fuel injection in conventional system;
[0033] Fig. 3b illustrates multiple fuel injections with Engine Control Unit (ECU), in accordance with an embodiment of the present disclosure;
[0034] FIG. 4 illustrates flow of fuel from Point of Injection (POI) to Point of Optimum Sauter Mean Diameter (SMD) of each of the fuel injector in the intake manifold, in accordance with an embodiment of the present disclosure; and
[0035] Fig. 5 illustrates a method for reducing emissions, port wall wetting, and improving fuel economy of an internal combustion (IC) engine having a port fuel injection mode where a plurality of fuel injectors are positioned in an Intake Manifold, in accordance with an embodiment of the present disclosure.
[0036] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in a computer-readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.
DETAILED DESCRIPTION
[0037] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to

clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0038] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0039] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[0040] In addition, the descriptions of "first", "second", "third", and the like in the present invention are used for the purpose of description only, and are not to be construed as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may include at least one of the features, either explicitly or implicitly.
[0041] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.

[0042] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0043] Micro-Controller: It is a compact integrated circuit designed to govern a specific operation in an embedded system. A typical microcontroller includes a processor, memory and input/output (I/O) peripherals on a single chip. Generally, microcontrollers are designed to be readily usable without additional computing components because they are designed with sufficient on board memory as well as offering pins for general I/O operations, so they can directly interface with sensors and other components.
[0044] FIG. 1 illustrates Engine Control Unit (ECU) coupling with other components to determine fuel injection. Referring to fig. 1 and fig. 2 together, the present ECU 100 having a fuel controller 200 coupled with a plurality of injectors 101, a lambda sensor 102 positioned in exhaust system, a coolant temperature sensor 103 of an Internal Combustion (IC) engine, and an engine speed sensor 104 having a cam shaft sensor and crankshaft sensor to decide the speed of the engine. The ECU 100 maintains fuel supply to the IC engine to maintain homogenous air-fuel mixture for better fuel efficiency and better emission performance.
[0045] The ECU 100 receives inputs from the coolant sensor 103, the engine speed sensor 104, and the lambda sensor 102 to determine the quantity of fuel to be supplied. The ECU 100 is coupled with the plurality of fuel injectors 106 positioned in an air intake manifold to mix the injected fuel with the air. Each of the fuel injector from the plurality of fuel injectors 106 is positioned before the intake valve of the combustion cylinder.
[0046] The ECU determines cold/hot start of the engine upon analysing
the coolant temperature based on the inputs received from the coolant sensor 103.

Upon cranking, the ECU activates the starter motor to move the engine at stable engine speed. Upon achieving the stable engine speed, i.e., engine starting speed, the ECU 100 determines the piston position in the combustion cylinder based on the engine speed sensor 104 having camshaft sensor and crankshaft sensor. Upon determining the cylinder identification, the ECU 100 calculates the fuel quantity to be supplied to the engine. The ECU 100 calculates fuel injection time based on the calculated fuel quantity to be supplied. The plurality of fuel injectors 106 operating coupled with the ECU 100 opens to supply or inject fuel in the air intake manifold for mixing of the fuel with the air.
[0047] Once the IC engine is started, the ECU 100 receives feedback signals from the lambda sensor 102 regarding oxygen content in the emissions. Based on the feedback signals received from the lambda sensor 102, the ECU 100 determines if engine is operating fuel rich or fuel lean to calculate the injection quantity for the next cycle and changes the air fuel mixture to control the emissions.
[0048] The ECU 100 calculates the fuel quantity to be supplied based on the feedback signals received from the lambda sensor 102 and determine the fuel injection time based on the calculated fuel quantity to be supplied.
[0049] Referring to fig. 3a, the total fuel quantity is injected in a single injection in the air intake manifold in convention system which creates port wall wetting and emissions issues.
[0050] The ECU 100 divide the single fuel injection time into plurality of fuel injections by keeping the total fuel injection quantity same as calculated based on the inputs received from the lambda sensor 102 and the engine speed sensor 104. With splitting or dividing of single fuel injection into the plurality of fuel injections allow the fuel to penetrate in air present in the air intake manifold to form a homogenous mixture.
[0051] Referring to fig. 1 and Fig. 2, the ECU 100 includes a fuel controller 200 which can be implemented to control or maintain fuel injection or fuel supply

to the IC engine 105 based on the inputs received from the coolant sensor 103, engine speed sensor 104, and the lambda sensor (102).
[0052] In another embodiment, the fuel controller 200 can be a standalone device that is in communication with the coolant sensor 103, engine speed sensor 104, and the lambda sensor 103 to determine the fuel quantity to be supplied to the IC engine. The fuel controller 200 (hereinafter can be referred as controller 200) includes a micro-controller and a memory.
[0053] In an embodiment, implementation of the present subject matter is not limited to micro-controller, it can be implemented in other processing units. In an embodiment, in place of micro-controller, the fuel controller 200 may have a processor(s), an interface(s), and a memory which are working together to achieve the function, i.e., maintaining fuel supply to the IC engine as per pre-define instructions and conditions and real time inputs received from the plurality of coupled sensors.
[0054] The memory may include data that is either stored or generated as a result of functionalities implemented by the micro-controller. Additionally, memory can be organized using data models, such as relational or hierarchical data models. The memory may store data, including temporary data and temporary files, generated by the micro-controller for performing the various functions of the fuel controller 200. The memory may pre-stores the data for processing of the micro-controller. In an embodiment, the micro-controller may have its own memory for processing and storing the pre-stored data that may be used during processing.
[0055] As shown in the fig. 2, the Fuel controller 200 is coupled with coolant sensor 103, the engine speed sensor 104, and the lambda sensor 102. The Fuel controller 200 is coupled with the plurality of fuel injectors 101 positioned in the air intake manifold to mix the fuel with air in the air intake manifold. The present IC engine uses port fuel injection mode to supply fuel.

[0056] The fuel controller 200 calculates fuel quantity to be injected into the air intake manifold based on the engine speed sensor 104, the coolant sensor 103, and the lambda sensor 102. The fuel controller 200 calculates fuel injection time based the calculated fuel quantity to be supplied.
[0057] In a conventional system, as the signal form Lambda sensor is received in the ECU, the ECU detects if the system is running in Fuel Rich or Fuel Lean. If engine is Fuel Lean or rich, the ECU operates injectors for longer duration with respect to previous injection time so that amount of the fuel injected is increased. In case of Fuel Lean, reverse happens.
[0058] With the proposed system, a delay time will be stored in the ECU, which will be different for different injector type. The ECU will divide the total fuel to be injected in such a way that the time between injections will be the delay time.
[0059] The fuel controller 200 divides the fuel injection time into a plurality of fuel injections by keeping the total fuel injection quantity same. The splitting of total injection time into plurality of small fuel injections allows the fuel to penetrate into air to maintain air-fuel ratio at stoichiometric.
[0060] Referring to fig. 3b, in port fuel injection mode, the fuel injectors 101 injects the fuel into the air intake manifold during exhaust stroke of the previous cycle. The fuel controller 200 divide the single fuel injection time into a plurality of fuel injections with small fuel injections time by keeping the same fuel injection quantity.
Single Injection = Inj 1 + Inj 2 +Inj 3 +Inj n
[0061] The fuel controller 200 stores the pre-defined time difference 'X' between two consecutive fuel injections from the plurality of fuel injections by The time difference 'X' is the time required for fuel quantity injected in first fuel injection to homogenously mix with air.
[0062] In the fig. 4, the fuel is injected at point of injection 401 from the fuel injectors and at point of optimum sauter mean diameter (SMD) 402 the injected

fuel atomize. The time required for fuel to flow from point 401 to point 402 is the time difference between two consecutive fuel injections. Based on the optimum SMD point 402, the position of the fuel injector can be decided in the air intake manifold nearer to the intake valve of the combustion chamber so that port wetting and fuel puddle can be reduced.
[0063] Accordingly, total number of injections can be determined by dividing the total injection time with time required for fuel to flow from point 401 to point 402. The fuel quantity injected by first fuel injection homogeneously mixes with air in the air Intake Manifold () before injection of second fuel during single exhaust stroke of the previous cycle. The plurality of fuel injections maintains Air-fuel ratio at stoichiometric to reduce emissions, reduce port wall wetting and to improve fuel efficiency.
[0064] In an aspect, number of fuel injections in the plurality of fuel injections can two or three or more to maintain air-fuel ratio at stoichiometric in the intake manifold.
[0065] FIG. 5 illustrates a method 500 for reducing emissions, port wall wetting, and improving fuel economy of an internal combustion (IC) engine having a port fuel injection mode where a plurality of fuel injectors 101 are positioned in an Intake Manifold. The order in which the method 500 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any appropriate order to carry out the method 500 or an alternative method. Additionally, individual blocks may be deleted from the method 500 without departing from the scope of the subject matter described herein.
[0066] At block 502, the method includes judging hot/cold start of the engine by the ECU by analysing the coolant temperature based on the inputs received from the coolant sensor 103.

[0067] At block 504, the method includes activating the starter motor by supplying power from the auxiliary battery and cranking the engine to achieve stable engine speed.
[0068] At block 506, the method includes identifying, by the ECU, the piston position in the combustion cylinder based on inputs received the engine speed sensor 104 having camshaft sensor and crankshaft sensor.
[0069] At block 506, the method includes calculating, by fuel controller 200, fuel quantity to be injected into the intake manifold based on the inputs received from the coolant sensor 103, the engine speed sensor 104, and the lambda sensor 102.
[0070] In an aspect, the method further includes calculating fuel quantity to be injected into the intake manifold based on feedback signal received from Lambda sensor 102 to maintain air-fuel ratio at stoichiometric to reduce emissions.
[0071] At block 508, the method includes calculating, by the fuel controller 200, fuel injection time based the calculated fuel quantity to be injected in single injection or pulse into the air intake manifold.
[0072] In another embodiment, the method includes converting the calculated required fuel quantity into injection time/pulse into the air intake manifold.
[0073] At step 510, the method includes dividing/splitting the calculated fuel injection time into a plurality of fuel injections or pulse mode by keeping total fuel injection quantity same. By dividing/splitting the total fuel injection time into plurality small fuel injections allows fuel to penetrate in air to form a homogeneous mixture by maintaining air-fuel mixture to stoichiometric.
[0074] At block 512, the method includes adjusting the split injection time/pulse into the combustion cylinder to achieve homogeneous mixture by maintaining air-fuel mixture to stoichiometric.
[0075] Once the IC engine is started, the ECU 100 receives feedback signals from the lambda sensor 102 regarding oxygen content in the emissions. Based on

the feedback signals received from the lambda sensor 102, the ECU 100 changes the air fuel mixture to control the emissions.
[0076] In an aspect, the method includes determining time difference between two consecutive fuel injections from the plurality of fuel injections by measuring time required for fuel to flow from Point of Injection (POI) to Point of Optimum Sauter Mean Diameter (SMD) of each of the fuel injector 101 from the plurality of fuel injectors 101.
[0077] In an aspect, the method includes injecting the plurality of fuel injections into the air intake manifold during exhaust stroke of the IC engine.
[0078] In an aspect, the method includes determining number of small fuel injections in single exhaust stroke of the IC engine to maintain Air-fuel ratio at stoichiometric.
[0079] In an aspect, the method includes selecting number of fuel injections in the plurality of fuel injections from two or three or more to maintain air-fuel ratio at stoichiometric in the intake manifold to reduce emissions, port wall wetting, and to improve fuel efficiency.
Technical advantages:
[0080] With the present Engine Control Unit (ECU) a homogenous air-fuel mixture is obtained in the air intake manifold that reduces emissions and port wall wetting.
[0081] With the present ECU, the homogenous air-fuel mixture is obtained which improves fuel economy of the vehicle.
[0082] With the present ECU, it becomes possible to move the fuel injectors closer to engine intake valve. If the injection quantity is reduced or divided into smaller injections, the fuel injected first will be completely mix with air before second injection starts. So, there is less liquid fuel to wet the surface. With this condition we can move the injector closer.

[0083] With the present ECU, there is no requirement of any other new hardware, existing hardware can be optimized to obtain technical advanced results.
[0084] The above description does not provide specific details of the manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art can choose suitable manufacturing and design details.
[0085] It should be understood, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, as apparent from the discussion herein, it is appreciated that throughout the description, discussions utilizing terms such as "receiving," or "determining," or "retrieving," or "controlling," or "comparing," or the like, refer to the action and processes of an electronic control unit, or similar electronic device, that manipulates and transforms data represented as physical (electronic) quantities within the control unit's registers and memories into other data similarly represented as physical quantities within the control unit memories or registers or other such information storage, transmission or display devices.
[0086] Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0087] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated

alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
[0088] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

WE claim:

1.An Engine Control Unit (100) for reducing emissions and improving fuel
economy, the ECU (100) comprising:
a fuel controller (200) coupled with a plurality of fuel injectors (101) positioned in an air intake manifold for controlling fuel injection in split mode, the fuel controller (200) configured to:
calculate fuel quantity to be injected into the air intake manifold; calculate fuel injection time required to inject the calculated fuel quantity; and
divide the fuel injection time and the fuel quantity into a plurality of fuel injections to maintain air-fuel ratio at stoichiometric.
2. The Engine Control Unit (100) as claimed in claim 1, wherein the fuel controller (200) is coupled with a lambda sensor (102) to calculate fuel quantity to be injected into the air intake manifold based on feedback signal received from Lambda sensor (102).
3. The Engine Control Unit (100) as claimed in claim 1, wherein the plurality of fuel injections is made in the air intake manifold during an exhaust stroke of previous cycle of an Internal combustion (IC) engine.
4. The Engine Control Unit (100) as claimed in claim 1, wherein the fuel controller (200) determines:
time difference (X) between two consecutive fuel injections from the plurality of fuel injections by measuring time required for fuel to flow from Point of Injection (POI) (401) to Point of Optimum Sauter Mean Diameter (SMD) (402) of each of the fuel injector (101) from the plurality of fuel injectors (101).
5. The Engine Control Unit (100) as claimed in claim 4, wherein an injected
fuel quantity by first fuel injection homogeneously mixes with air in the air
Intake Manifold before second fuel injection during single exhaust stroke of
the previous cycle.

6. The Engine Control Unit (100) as claimed in claim 1, wherein the fuel controller (200) determines number of fuel injections in single exhaust stroke of the engine to maintain Air-fuel ratio at stoichiometric.
7. The Engine Control Unit (100) as claimed in claim 1, wherein number of fuel injections in the plurality of fuel injections is selected to maintain air-fuel ratio at stoichiometric in the air intake manifold to reduce emissions, port wall wetting, and to improve fuel efficiency.
8. A method (500) for reducing emissions, port wall wetting, and improving fuel economy of an internal combustion (IC) engine having a port fuel injection mode where a plurality of fuel injectors (101) are positioned in an air Intake Manifold, the method (500) comprising:
calculating (502) fuel quantity to be injected into the air intake manifold;
calculating (504) fuel injection time based on the calculated fuel quantity; and
dividing (506) the fuel injection time and the fuel quantity into a plurality of fuel injections to maintain air-fuel mixture to stoichiometric.
9. The method (500) as claimed in claim 8, wherein the method (500)
comprises:
calculating fuel quantity to be injected into the air intake manifold based on feedback signal received from Lambda sensor (102) to maintain air-fuel ratio at stoichiometric to reduce emissions.
10. The method (500) as claimed in claim 8, wherein the method (500)
comprises:
injecting the plurality of fuel injections into the air intake manifold during exhaust stroke of previous cycle of the IC engine.
11. The method (500) as claimed in claim 8, wherein the method (500)
comprises:
determining time difference (X) between two consecutive fuel injections from the plurality of fuel injections by measuring time required for fuel to flow from Point of Injection (POI) (401) to Point of Optimum

Sauter Mean Diameter (SMD) (402) of each of the fuel injector (101) from the plurality of fuel injectors (101).
12. The method (500) as claimed in claim 8, wherein the method (500)
comprises:
determining number of fuel injections by keeping fuel injection quantity same as single injection in single exhaust stroke of the IC engine to maintain Air-fuel ratio at stoichiometric.
13. The method (500) as claimed in claim 8, wherein the method (500)
comprises:
selecting number of fuel injections in the plurality of fuel injections to maintain air-fuel ratio at stoichiometric in the air intake manifold to reduce emissions, port wall wetting, and to improve fuel efficiency.