24-12-2012, 05:53 PM
Ignition System
Ignition System.ppt (Size: 1.87 MB / Downloads: 141)
Introduction
Provides a method of turning a spark ignition engine on & off.
Operates on various supply voltages (Battery & Alternator)
Produces high voltage arcs at the spark plug electrode.
Distributes spark to each plug in correct sequence.
Times the spark so that it occurs as the piston nears the TDC on the
compression stroke.
Varies the ignition timing as engine speed, load and other conditions
change.
Ignition Circuits
PRIMARY CIRCUIT
Includes all the components
working on low voltage
(Battery, Alternator).
SECONDARY CIRCUIT
Consists of wires and points
between coil out-put and the
spark plug ground.
Distributor Rotor
Transfers voltage from the distributor cap
center terminal(coil) to distributor cap
outer terminals(spark plugs).
Sometimes the firing order can be found
on the intake manifold.
Methods of controlling Timing
Electronic Advance Sensors input influences the ignition timing.
Crank shaft Position Sensor (RPM)
Cam Position Sensor (tells which
cylinder is on compression stroke)
Manifold Absolute Pressure (MAP)
(engine vacuum and load)