Multi Point Fuel Injection System
Sanoj Kumar
Thermal Engg.
2236010

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”

 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

OBJECTIVES
 power output
 fuel efficiency
 emissions performance
 ability to accommodate alternative fuels
 reliability
 drivability and smooth operation
 initial cost
 maintenance cost
 diagnostic capability
 range of environmental operation
 Engine tuning

HISTORY AND
DEVELOPMENT
 Herbert Akroyd Stuart developed the first system
 The first use of direct gasoline injection was on
the Hesselman engine invented by Swedish
engineer Jonas Hesselman in 1925
 One of the first commercial gasoline injection
systems -a mechanical system developed by Bosch
and introduced in 1952 on the Goliath GP700 and
Gutbrod Superior 600

Mechanical fuel injection systems
Goliath GP700 Carrera 3.0
 Chevrolet introduced a mechanical fuel injection
option, made by General Motors' Rochester Products
division, for its 283 V8 engine in 1956

Electronic fuel injection
systems
 First commercial EFI system was Electrojector-
developed by the Bendix Corporation
 EFI system in the Rambler was a far more-
advanced setup
than the mechanical
types.
Rambler Rebel

 1958 Chrysler 300D, Dodge D500, Plymouth Fury,
and DeSoto Adventurer-the first series-production
cars equipped with an EFI system.
 D-Jetronic was first used on the VW 1600TL/E in
1967
VW 1600TL/E 1958 Chrysler 300D

SUPERSESSION 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

 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

 Exhaust air or oxygen sensor
 Engine temperature sensor
 Air flow sensor
 Throttle position sensor
 Manifold pressure sensor
 Camshaft position sensor
 Knock sensor
BASIC FUNCTIONS

FUNDAMENTALS OF
FUEL INJECTION
 MPFI Systems can either be:
• Sequential
• Simultaneous
• Group
 These techniques result in better ‘power balance’
amongst the cylinders, higher output from each
one of them, along with faster throttle response

 'Sequential' is the best from the above
considerations of power balance/output
 “Sefi’’-Sequential Electronic Fuel Injection -
technically is the best of the above variants of
MPFI
 The ‘on-board’ ECU primarily controls the
Ignition Timing and quantity of fuel to be
injected

VARIOUS INJECTION
SCHEMES
MPFI
system
Port
injection
Throttle
Body
injection
D-MPFI
System
L-MPFI
System

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

Throttle Body Injection System

D-MPFI System

L-MPFI System

CONCLUSION
 Improved fuel consumption
 Better for the environment
 Better performance