3. ADVANTAGES OF FUEL INJECTION OVER CARBURETOR
☼ Fuel injection has no choke, but sprays atomized fuel directly into the
engine.
☼ Electronic fuel injection also integrates more easily with computerized
enginecontrol systems.
☼ Multi port fuel injection delivers a more evenly distributed mixture of
airand fuel toeach of theengine's cylinders.
☼ Sequential fuel injection improves powerand reduces emissions.
4. Petrol injection system
Gasolinedirect injection
(GDI)
Indirect injection
( manifold injection)
Single point injection Multi point fuel injection
(MPFI)
Throttle injection Port injection
Throttle injection Port injection
TYPES OF PETROL INJECTION
SYSTEM
5. ⚫In indirect fuel is injected into theairstream before
entering thecombustionchamber.
⚫And in direct injection system fuel is injected directly
inside thecombustionchamber.
Fuel injector
Indirect injection Direct injection
Combustion
Chamber
Inlet valve
6. Single Point Injection system
⚫The earliest & simplest type of fuel injection, single
point simply replaces the carburetor with one or two
fuel injector nozzles in the throttle body, which is the
throatof theengine’s air intake manifold.
⚫Single point injection system meters fuel betterthan a
carburetorand is lessexpensiveand easier toservice.
7. Throttle Injection
⚫The indirect injectioncan beclassified as single point
injectionand multi point fuel injection.
⚫The single point injection also called Throttle
injection in which fuel is injected atone place in
throttle body, and the mixturesupply todifferent
cylindersas shown in fig…
8.
9. Port injection
⚫In case of Port injection also called multi point
fuel injection, airsucks through throttle body, and
fuel is injected near inletvalveof every cylinderas
shown in fig….
10.
11. Multi Point Fuel Injection System
(MPFI)
⚫MPFI system is widely used in petrol engine in placeof
carburetor.
⚫Purposeof MPFI is supplyproper A/F ratio toeach
cylinderof engine.
⚫Fuel tank > Pump > High pressure petrol > Distributor
> Fuel injector > Cylinder
⚫Nowadays MPFI systemcontrol by Electric Control
Module (ECM).
⚫Ecm receives signal from different sensors.
⚫ECM receives signal and send to the solanoid operated
fuel injector to meter and inject right amount of fuel at
right time.
12. There are different typeof sensors in MPFI system.
1. Inlet manifold pressuresensor
2. Air flow sensor
3. Engine speed sensor
4. Throttleposition sensor
5. Coolant temperaturesensor
6. Inletair temperaturesensor
7. Knock sensor
8. Exhaustgas sensor
13. Direct injection (GDI)
⚫Thesesystems inject the fuel directly into thecombustion
chamber, either during the intake stroke or during the
compression stroke.
⚫Thereare two basic typeof GDI, either injectionof gasoline
alone, oraduel injection of gasolineand air together.
⚫Injection of fuel alone is usually done during the
compression stroke and is somewhat similar to fuel
injection in CI engine. Because of the very short time
available forvaporizationand mixing with air, very fine
droplets of fuel are required, as are high turbulenceand
bulk mass motion within thecombustion chamber
14. ⚫Injectorpressure must be higher than that require for
port injection.
⚫This is because of the higher pressure into which the
fuel is being injected, and becauseof the requirement
for finerdropletsof fuel.
⚫Pressure required for fuel injection is above 40 to 65
bar.
⚫Modern gasolineengine may utilized Direct injection
using electriccontrol.
15. Fuel injection in two wheelers
1.It usesadvanced sensorsand actuators
tocalculateand delivertheoptimum
amount of fuel to the engine –
enhancing both performanceand
mileage.
2.more responsive leading to quick
initial pickupand delivering smooth
passing acceleration.
3.Itachievesa 14% improvement* in
fuel economy.
4.its intake/exhaustvalve layout is
designed to best match the
hemispherical combustion chamber. In
combinationwith theoptimized intake
and exhaust port shapes, this design
increases combustion speed and helps
achieveexcellentcombustion
efficiency. The new engine further
improves fuel efficiencyand the feeling
of acceleration while retaining the
excellentperformancequalitiesof the
currentFZ engine.
16. Advantages of Direct Injection
⚫Bettorvaporization
⚫Highervolumetricefficiency
⚫Easycold starting
⚫Lowerexhaustemission
⚫Higherefficiency and better mileage
