This document discusses multipoint fuel injection (MPFI) systems for gasoline engines. It describes two types of MPFI systems - port injection and throttle injection. In port injection, fuel injectors are placed in the intake manifold near the intake ports to spray fuel into the incoming air before it enters the cylinders. In throttle injection, the system is similar to a carburetor with a throttle valve controlling air intake and sensors controlling fuel mixing. The document outlines the four main components of an MPFI system - the air intake, fuel delivery, electronic control, and emission control systems. It provides details on various sensors used in the electronic control system like throttle position, manifold pressure, engine temperature, oxygen, and vehicle speed sensors. Advantages

4. 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).

5. CLASSIFICATION OF MPFI
 By the Placing of the injector it is further classified into two
types.
I. Port Injection system .
II. Throttle Injection system

6. 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 .

7. Throttle Injection system
 This 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.

8. Type Of Injection System

9. Sketch of MPFI:

10. 8 &12 Cylinder MPFI

11.  The system has four major components they
are
1. Air intake system
2. Fuel delivery system
3. Electronic control system[E.C.U]
4. Emission control system

12. 1. Air intake system

13. 2.Fuel delivery system
Fuel
return
Fuel rail

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

15.  1.THROTTLE POSITION SENSOR:
 Throttle valve opening degree to send the signal in
E.c.u
 Location:
 it is mount on throttle body

16.  [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

17.  Engine coolant temperature sensor It is incorporated with
coolant and measures the coolant temperature.
LOCATION:
 it is mount on thermostate valve.

18. The temperature air entering the engine
So find air+fuel mixture.
LOCATION:
 it is mount on air cleaner

19.  To indicate the vehicle speed sensor sense to send the
signal.
LOCATION:
 it is mount on Tramission system

20. 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

21. 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.

22. LIMITATIONS Of MPFI:
1. Cost is high.
2. Electrical system is more
3. Valve is Required.
4. Intake Manifold control only air not Fuel .