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ppt on mpfi


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MPFI(Multi Point Fuel Injection) : 

MPFI(Multi Point Fuel Injection) Done By MUKUL R0ll no:44

Introduction : 

Introduction In petrol vehicles carburetor is used for supplying air fuel mixture to the cylinder In response to the recent demand for cleaner exhaust emission improved drivability and mileage carburetor is not sufficient In place of the carburetor MPFI system is used in vehicles MPFI system is injects fuel into individual cylinders based on commands from engine control module The MPFI gives higher output, faster throttle response under varying driving conditions

Components of MPFI : 

Components of MPFI The system has four major components they are Air intake system Fuel delivery system Electronic control system Emission control system Air intake system It includes air filter, throttle body, intake manifold, and finally drawn into the combustion chamber

Air intake system : 

Air intake system Throttle body It consist of throttle valve, T P sensor, which detect the throttle valve opening Idle air control valve which supplies bypass air depending on the engine condition Fuel delivery system It includes fuel pump, fuel filter and injector Fuel pump ECM controls its operation and centrifugal pump is used to pump the fuel The fuel pump also has a check valve to keep some pressure in fuel feed line even when fuel pump is stopped

Pressure regulator system : 

Pressure regulator system It keep the fuel pressure applied to the injector 2.9kg/cm^2 Injector Each cylinder have one injector It inject the fuel into the inlet manifold according to the signal from ECM Electronic control system The electronic control system consist of various sensors which detect the state of engine and driving conditions

Control systems are, : 

Control systems are, Fuel injection control system In which ECM controls the timing of fuel injection according to the signals from various sensors Injection time is calculated on the basis of engine speed Idle speed control system It keep the engine idle speed as specified at all times

Fuel pump control system : 

Fuel pump control system ECM controls the ON\OFF operation of the fuel pump Ignition control system This system controls ignition timing The ECM judges the engine conditions by using signals from various sensors selects suitable ignition timing Controls of this system includes Ignition timing at the engine start Ignition timing after engine start

Radiator fan control system : 

Radiator fan control system Radiator fan motor is turned ON and OFF by using relays Radiator fan motor turned ON at below 98degree Celsius and OFF at below93degree Celsius Engine Control Module It consist of micro computer, analogue\digital converter It controls fuel injector, IAC valve, fuel pump relay ….etc

Working : 


Functional division of MPFI : 

Functional division of MPFI

On-board diagnostic system : 

On-board diagnostic system ECM diagnosis troubles which may occur in the engine when ignition switch is ON and the engine is running, it indicates trouble to the driver by flashing malfunction indication lamp And it stores the data about the trouble in ECM back up memory Emission control system It includes evaporative canister Evaporative emission control system This is used to prevent emission of fuel vapour

Sensors used in MPFI : 

Sensors used in MPFI Manifold absolute pressure sensor This sensor senses pressure change in the intake manifold The signals from the MAP is used by the ECM to control fuel injection pressure Throttle position sensor This is connected to throttle valve shaft on the throttle body and detects throttle valve opening Intake air temperature sensor It located on the air cleaner outlet hose and constantly measures the temperature of air entering to the intake manifold By sensing the temp. the ECM adjusts fuel injection quantity

Engine coolant temperature sensor : 

Engine coolant temperature sensor It is incorporated with coolant and measures the coolant temperature Oxygen sensor Oxygen sensor is installed on the exhaust manifold to detect the concentration of oxygen in the exhaust gases It is necessary to keep the air fuel ratio within a narrow range, and keep it in a stochiometric air fuel ratio Vehicle speed speed sensor The vehicle speed sensor is located on the transmission gear box or speedometer

Cam shaft position sensor : 

Cam shaft position sensor Using this signal ECM identifies cylinder whose piston is in the compression stroke Crank shaft position sensor ECM uses this signal for knowing the engine speed and cylinder identification

Advantages of MPFI : 

Advantages of MPFI 1) More uniform A/F mixture will be supplied to each cylinder; hence the difference in power developed in each cylinder is minimum. Vibration from the engine equipped with this system is less, due to this the life of engine components is improved. (2) No need to crank the engine twice or thrice in case of cold starting as happens in the carburetor system. (3) Immediate response, in case of sudden acceleration / deceleration.

Advantages of MPFI : 

Advantages of MPFI Since the engine is controlled by ECM* (Engine Control Module), more accurate amount of A/F mixture will be supplied and as a result complete combustion will take place. This leads to effective utilization of fuel supplied and hence low emission level. (5) The mileage of the vehicle will be improved.

Conclusion : 

Conclusion Almost all vehicles in India are changing to the MPFI because of law emissions, improved mileage and drivability Since the engine is controlled by micro computer more accurate amount of A/F mixture will be supplied and as a result complete combustion will take place. This leads to effective utilization of fuel supplied and hence low emission level. It reduces wastage of fuel by the use of sensors and other control systems


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