Fuel Injection System

Suraj Kumar Gupta

(1204240054)

Contents

a. Introduction

b. Objectives

c. Injector

d. Functioning

e. Injection schemes

f. Advantages

g. Disadvantages

h. Conclusion

i. Bibliography

Introduction

Fuel injectionatomizes the fuel by pumping it through a small nozzle under high pressure

Objectives

Power output

Fuel efficiency

Emissions performance

Acceptable to alternative fuels

Reliability

Drivability and smooth operation

Initial cost

Maintenance cost

Engine tuning

Injector

Electromechanical device

Controlled by ECM

How long it stays open determined

by:

Engine temp

Engine load

Throttle position

O2 sensor voltage

Functioning

1. Leak off

2. Pressure adjusting shim

3. Pressure spring

4. Injector body

5. High pressure fuel supply

6. Pressure pin

7. Needle valve

8. nozzle retaining nut

9. Nozzle

Injectors in operation

Various Injection Schemes

Single Point Injection (SPI)

Continuous InjectionCentral Port Injection (CPI)

Multi Point Injection (MPI)

Direct Injection

Injection

Injects Fuel at throttle

body

Fuel Pressure-10-15 psi

It was used in 1980s

Flows at all times

Mainly used in aircraft engine

Tubes with Poppet valves

are used Batch fire

Injects into intake ports

40-60 psi

Sequential Batched

Injection

Fuel is Injected into the combustion

chamber

26000 psi

Injection

Advantages

It requires little regular maintenance.

Very good atomization of fuel by injection nozzle. The engine's overall power

output improves.

It eliminates the risk of carburettor icing.

Disadvantages

It requires several peripheralcomponents which leads increasedbasic cost.

Technology is morecomplex.

Definite tuning required for every engine and itscomponent.

conclusion

Here I conclude my speech stating that proper functioning offuel injector should be ensured for proper functioning of engine.

Though there are some disadvantages , Fuel Injection System areused extensively these days.

Bibliography

• A course in internal combustion engine by M.L. Mathurand R.P. Sharma.

• Internal combustion engine by V. Ganesan.

• Internal combustion engine fundamentals by J.B. Heywood.

• http://www.wikipedia.org

• http:// www.sae.org

• http:// www.ecollege.com

• http:// www.engineeringexplained.com

• http://www.brighthubengineering.com

• http://www.howstuffworks.com