Petrol Fuel Injection

8/9/2019 Petrol Fuel Injection

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FUEL INJECTION



Fuel Injection•Limitation of carburetor/Necessityof fuel injection

• In Multi cylinder engine – difficult for a single

carburetor to supply uniform quality and quantity.• Venturi throat of the carburetor causes a restrictionin the passage of air flow to the engine. If the throatis made a larger for this reason, the problem of

suitable mixture supply• Carburetor has many wearing parts, After wear itsoperates less efficiency.

• Loss of volumetric efficiency due to flow of mixturein choke tube, inlet pipe bends.



Merits of Fuel Injection• Absence of Venturi – No Restriction in Air Flow/Higher

Vol. E./Torque/Power• Mnifol! "rnch Pi#es Not concerne! with Mi$ture

Pre#rtion %MP&'

• "etter Accelertion Res#onse %MP&'

• Fuel Ato(i)tion *enerll+ &(#ro,e!

• -se of ensors to Monitor #erting Pr(eters/*i,esAccurte Mtching of Air/fuel Require(ents0 &(#ro,esPower1 Re!uces fuel consu(#tion n! E(issions

• Precise in Metering Fuel in Ports

• Precise Fuel 2istribution "etween 3+lin!ers %MP&'

• Fuel Trns#orttion in Mnifol! not require! %MP&' so no4ll 4etting

• Fuel urge 2uring Fst 3ornering or He,+ "r5ingEli(inte!

•

A!#tble n! uitble For u#erchrging %P& n! MP&'



TYPE OF INJECTION SYSTEM

• Direct injectionsystem

Direct injection

forces fuel into the enginecombustion chambers.Diesel injection systems

are direct type

• Indirect injectionsystem

An indirect injection

system sprays fuel into the

engine intake manifold.Most

gasoline injection

systems are of this

type.





Also 3lle! Mnifol! &n6ection or

ingle Point &n6ection %P&' orThrottle "o!+ &n6ection %T"&'

The point or location of fuelinjection is one way toclassify a gasoline injectionsystem.

A single-point injectionsystem, also call throttlebody injection (TBI), hasthe injector nozzles in a

throttle body assembly ontop of the engine. Fuel issprayed into the top center ofthe intake manifold

Mono point injection (or) Single pointinjection (or) Throttle body injection (TBI)



u pon nec on or Port fuel injection (PFI)

• A multi-Point injectionsystem, also called portinjection, has an injectorin the port (air-fuel

passage) going to eachcylinder. Gasoline issprayed into each intakeport and toward each

intake valve. Thereby, theterm multipoint (morethan one location) fuelinjection is used



FUEL INJECTION TYPES



MECHANICAL (CAM) CONTROLLEDGASOLINE INJECTION SYSTEM



ELECTRONICALLY CONTROLLEDGASOLINE INJECTION SYSTEM

• The supply of fuel and timing are controlled by Electronic is known as Electroniccontrolled gasoline injection system.

• This mainly used for Spark ignition system(SI) Engine.

• It Consists of four units.

1. Fuel delivery system 2. Air induction system

3. Sensors and Air flow control system

4. Electronics control units (ECU)












Fuel circuit components

Common rail and Pressure sensoFuel line hoses

Fuel filtersFuel pumps



Automotive Engineering

MECHANICAL FUEL PUMP

&N7ET VA7VE

2&APHRA*MPR&N*

2&APHRA*M

2E7&VER8VA7VE

2rin Hole

Acts as a breather fordiaphragm, but is alsoa tell-tale hole - fuelwill leak out of it if thediaphragm splits. Oilwill leak out if the

piston rod seal fails.

P-77 R2EA7

F-E7 &N F-E7 -T

E33ENTR&3 N3AMHAFT



Automotive Engineering

Electric Fuel Pumps - Low Pressure

3ontct "re5er Points

Mgnet 3oil

Return #ring

utlet Vl,e

utlet 3onnection

Electricl u##l+ 3onnection Pushro!

@ Mgnet Ar(ture

2i#hrg( Asse(bl+

9B &nlet Vl,e

99 &nlet 3onnection

9: Filter

9 :

;

<=

9:

99

9B

@?

>



FUEL INJECTOR



Controlling Parameters to Sense(Some of the Parameters)

1.Engine Speed

2.Amount of Inlet Air (Engine Load)

3.Throttle Position

4.Air Temperature5.Coolant Temperature

6.Altitude

7.Cranking Speed

8.Exhaust Oxygen Concentration

9.Battery Voltage



Petrol Fuel Injection

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