WELCOME

P.A.C.RAMASAMY RAJA POLYTECHNIC COLLEGE

DEPARTMENT OF MECHANICAL ENGINEERING

MULTI POINT FUEL INJECTION SYSTEM (MPFI)

PRESENT BYG.MATHANKUMAR

FINAL YEAR MECHANICAL

INTRODUCTION To Supply a proper Ratio of Air+fuel mixture to Cylinder.

Without usage of Carburetor to mixing the Fuel and air In SI Engine.

Varied the Piston speed using Advanced sensors (ECU).

CLASSIFICATION OF MPFI By the Placing of the injector it is further classified

into two types.I. Port Injection system .II. Throttle Injection system

Port Type system:The Injector is Placed in the Intake Manifold near

the intake Port .The Injector Sprays fuel into the Air inside the

manifold .Fuel & Air mix in Uniform manner And this mixture

Entered into Cylinder .

Throttle Injection systemThis is similar to carburetor Body with throttle

valve controlling the amount of Air entering intake manifold .

The sensor is used to control the fuel mixing level.

Type Of Injection System

Sketch of MPFI:

8 &12 Cylinder MPFI

The system has four major components they are

1. Air intake system2. Fuel delivery system3. Electronic control system[E.C.U]4. Emission control system

COMPONENTS OF MPFI

1. Air intake system

2.Fuel delivery system

Fuel return

Fuel rail

1. Electronic control system[E.C.U]

1.THROTTLE POSITION SENSOR: Throttle valve opening degree to send the

signal in E.c.uLocation: it is mount on throttle body

SENSORS:

[MAP] SENSOR: 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 ECU to control fuel injection pressure Throttle position.

LOCATION: it is mount on intake manifold

MANIFOLD ABSOLUTE PRESSURE SENSOR

Engine coolant temperature sensor It is incorporated with coolant and measures the coolant temperature.

LOCATION: it is mount on thermostate valve.

ENGINE COOLANT TEMPERATURE SENSOR

INTAKE AIR TEMPERATURE SENSORThe temperature air entering the

engine So find air+fuel mixture.LOCATION: it is mount on air cleaner

To indicate the vehicle speed sensor sense to send the signal.

LOCATION: it is mount on Tramission system

VEHICLE SPEED SENSOR

Senses the amount of oxygen in the engine exhaust and calculates air –fuel ratio. sensor output voltage changes in proportion to air –fuel ratio.

LOCATION: it is mount on exhaust manifold

OXYGEN SENSOR [O2 SESORS]:

Advantages of MPFI:I. Without using of carburetor the

product cost is Low.II. Engine Efficiency is High. III.Low Maintenance.IV.High Power to Engine.V. Emission is control. VI.Easy staring for cold condition.

LIMITATIONS Of MPFI:

1. Cost is high.2. Electrical system is more3. Valve is Required.4. Intake Manifold control only air not Fuel .

THANK YOU