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X431 PAD Scopebox User’s Manual
16
4 Automotive Ignition waveform
The ignition system is the system which has greatest impact on the
performances of gasoline engine, as the statistical data shows that nearly half
of the failures are caused by poor work of electrical system. And the
performance tests of engine often start from the ignition system. Nowadays
ignition system includes distributor and distributorless. Distributorless includes
independent ignition and simultaneous ignition.
1.
Distributor ignition system i.e. contact breaker with contact-controlled
ignition system (commonly known as the platinum) and contact breaker
with noncontact-controlled ignition system combined with magnet, hall
components or infrared.
2.
Independent ignition system: crankshaft sensor send out the ignition
timing signal and cylinder identification signal so that the ignition system
can send out ignition signal to specified cylinder in specified time, each
cylinder has its independent ignition coil.
3.
Simultaneous ignition system: two cylinders share one ignition coil, when
two cylinder pistons reach top dead center at the same time (one is
compression, another is the exhaust), two spark plugs will be ignited at
the same time, at this time, the ignition for the former cylinder is in
high-pressure low temperature gas mixture, the ignition is valid, while for
the latter one is in low-pressure high temperature exhaust gas, the
ignition is invalid.
X-431 PAD can test and analyze the secondary signal for various engine
ignition systems.
4.1 Secondary-distributor ignition analysis
Connections: Plug the BNC end of secondary ignition pickup into
CH1/CH2/CH3/CH4 channel of Scopebox, then connect the high-voltage clip
to high-voltage line, and crocodile clips to ground.
Tips: Common ignition sequence (the specific sequence is subject to the
actual engine ignition sequence)
