The document discusses multi-point fuel injection (MPFI) systems. It describes the components of an MPFI system, including the air intake system, pressure regulator system, control system, fuel pump control system, and functional divisions. An MPFI system injects fuel into individual cylinders based on commands from the engine control module. This provides faster throttle response and higher output under varying driving conditions compared to carburetor systems. The MPFI system can be divided into three main components: the electronic control unit, fuel system, and air induction system.

1. MULTI POINT FUEL
INJECTION

2.  INTRODUCTION
 COMPONENTS OF MPFI
 AIR INTAKE SYSTEM
 PRESSURE REGULATOR SYSTEM
 CONTROL SYSTEM
 FUEL PUMP CONTROL SYSTEM
 WORKING
 FUNCTIONAL DIVISIONS OF MPFI SYSTEM
 ADVANTAGE AND DISADVANTAGE
 CONCLUSION

3.  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

4.  The system has four major components they are
1.Air intake system
2.Fuel delivery system
3.Electronic control system
4.Emission control system
 Air intake system
 It includes air filter, throttle body, intake
manifold, and finally drawn into the combustion
chamber

5.  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

6.  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

7. 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

8.  ECM controls the ONOFF 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

10. The MPFI system consists of one fuel
injector placed near every intake valve and
directed towards it, in the fuel intake
manifold. Fuel is supplied to the injector
through a common rail. The amount of air
intake is decided by the car driver by
pressing the gas pedal, depending on the
speed requirement.

11. The air mass flow sensor near throttle valve and
the oxygen sensor in the exhaust sends signal to
ECU. ECU determines the air fuel ratio required
,hence the pulse width. Depending on the signal
from ECU the injectors inject fuel right into the
intake valve. The fuel sprayed at high pressure
gts atomized into fine particles and get mixed
with air. The air fuel mixture is sucked ito the
engine cylinder and the combustion takes place.

12.  The mpfi system can be functionally
divided into the following three main
components
1. Electronic control unit
2. Fuel system
3. Air induction system

13. No need to crank the engine twice or
thrice in case of cold starting as happens
in the carburetor system.
Immediate response, in case of sudden
acceleration / deceleration.
The mileage of the vehicle will be
improved

14. Hood Height of the Car is High.
Manifold Heat control System OR
Valve is Required.
Intake Manifold control only air not
Fuel.

15. The multi cylinder engines used distributors.
But very shortly MPFI system replaced the
distributors. The modern day cars use MPFI
engines ,which has electronic control in it. They
use the engine sensors, integrated chips to
monitor the fuel injection time and quantity The
multipoint fuel injection are also used in the
engines which use LP gas as the fuel, with very
less alterations in the gasoline run engine.