15-02-2010, 07:55 PM
[attachment=2132]
Introduction
Controlling of Engine operation electronically by electronic components.
Benefits to the motorist, more power, better mileage, a smoother idle and reduced operation expenses.
Cost of components come down.
Engine become smaller in size.
Basic components are¦¦¦
Electronic Control Module
Fuel Delivery System
Ignition System
Sensors
1.Electronic Control Module
It is a extremely reliable piece of hardware.
It process information hundreds of times per second.
It is actually a microprocessor.
It is programmed by the Manufacturer.
It controls the fuel delivery and ignition timing by receiving information from sensors.
2.Fuel Delivery System
The fuel line passes through a which feeds each injector and it passes through a pressure regulator.
The surplus fuel heading back to the tank in the return line. The air is taken from the atmosphere. It is mixed with fuel just before the inlet valve by the fuel injector.
This fuel delivery system is controlled by ECU to provide lean and rich mixtures depending on operating conditions.
3.Ignition System
To maximize the Engine output, spark should be at the precise moment.
Maximum combustion chamber pressure can be attained.
A mechanical advance distributor is used for this.
A spark advance map is developed and stored in the ECU.
As the speed increases, the spark should be advanced further.
4.Sensors
Throttle Position Sensor
The ECU senses how wide the throttle is opened.
The ECU controls fuel delivery and spark timing.
It consists of a wiper arm and resistor.
At idle, resistance is high, Voltage is .6-.9v.
As throttle presses, resistance decreases, voltage is 3.5-4.7v.
2.Exhaust Gas Oxygen Sensor
It is placed in Engineâ„¢s exhaust system.
Consists of Zirconium Dioxide cell, provide precise indication of stoichiometric A/F ratio.(14.7:1).
Zirconium Dioxide is the outer cell exposed to exhaust gas and inner electrode is exposed to ambient air.
The output varies from 0v-1v.
At stoichiometric point it produces .45v
It provides precise output voltage measurements.
Conclusion
While electronic engine management is still a complex undertaking, the results can be worth it for small engine OEMâ„¢S seeking an edge in performance, emissions or in minimizing the long-term operating costs of their product. Plenty of application assistance is available from the manufacturerâ„¢s of the ECU, fuel-delivery system and sensors needed to implement electronic engine management.
