Post on 08-Nov-2014
MULTI POINT FUEL INJECTION
SYSTEM
BY:GOURAV GUPTAROLL NO. 12ENROLLMENT NO. 71/09
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INTRODUCTION
MPFI- a technology used in petrol engines
Uses a small computer to control the car’s engine
In MPFI engine one fuel –injector is installed near each cylinder ,that is why it is called multi point fuel injection.
Before MPFI system, there was a technology called “Carburetor”
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The computer in the MPFI system decides what amount of fuel to inject
System also learns from the drivers driving habits
MPFI system makes engine fuel efficient
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OBJECTIVES
power output fuel efficiency emissions performance reliability drivability and smooth operation initial cost maintenance cost range of environmental operation
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SUPPERSESSION OF CARBURETORS
Extensive carburetor modifications and complexities were needed to approach stoichiometric engine operation
3 primary types of toxic emissions from an IC engine: CO, unburnt HC, and NOx
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Fuel injection systems have significantly evolved since mid 1980s.
Current systems provide an accurate, reliable and cost-effective method of metering fuel and with clean exhaust emissions-replaced carburetors in the marketplace
The carburetor remains in use in developing countries
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COMPONENTS OF MPFI SYSTEM
Air intake system Fuel delivery system Electronic control system
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AIR INTAKE SYSTEM
Throttle Body –
consist of throttle valve, T P sensor, which detect the throttle valve opening.
Ideal Air Control Valve – supplies bypass air depending on the engine condition.
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FUEL DELIVERY SYSTEM
Fuel Pump – consists of armature, magnet, impeller, brush,
check valve etc.
Pressure Regulator System – keeps the fuel pressure applied to the injector
higher than intake manifold at all times.
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Fuel Injector – injects fuel into the intake port of the cylinder head according to the signal from ECM
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ELECTRONIC CONTROL SYSTEM
Electronic Control Module –controls various devices according to the signals from the sensors.
Fuel Injection Control System –supplies the combustion chambers with air/fuel mixture of optimized ratio under widely varying driving conditions.
Fuel Pump Control System –ECM controls ON/OFF operation of the fuel pump
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Ignition Control System –system controls electronically the time of electric current flow to ignition primary coil as well as ignition timing.
Radiator Fan Control System –controls operation (ON/OFF) of the radiator fan motor
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Exhaust air or oxygen sensor Engine coolant temperature sensor Inlet air temperature sensor Air flow sensor Throttle position sensor Manifold pressure sensor Camshaft position sensor Crankshaft position sensor
SENSORS USED IN MPFI SYSTEM
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VARIOUS INJECTION SCHEMES
MPFIsystem
Port injection
Throttle Body
injection
L-MPFI System
D-MPFI System
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Port Injection
The injector is placed on the side of the intake manifold near the intake port
Every cylinder is provided with an injector in its intake manifold
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Throttle Body Injection System
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D-MPFI System
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L-MPFI System
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CONCLUSION
Improved fuel consumption
Better for the environment
Better performance
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References
www.howstuffworks.comwww.indiacar.comwww.carblogindia.comwww.indiacar.comwww.wikipedia.orgwww.crazyengineers.comwww.ehow.comwww.google.com (for images)
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