IGNITION SYSTEM
SUMMARY OF IGNITION SYSTEM
The ignition system is integrated with the fuel injection system. It is an electronic system
equipped with built-in power supply module. It can provide various kinds of optimum
ignition angular values. This task is being carried out through referencing of the input
instantaneous physical parameter related with the engine working conditions. With the help
of a circuit analyzing microprocessor, it is capable of writing in the various optimum ignition
values into the program.
Circuit of ignition system
1. Knock sensor 2. Ignition coil 3. Rotary sensor 4. Ignition switch
5. Relay 6. Ignition / Fuel injection ECU 7. Fuse
When ECU is breaking off the current of the primary coil, the resulted induction effect of the
secondary coil causes the voltage to rise (as high as 30,000V at idling speed), at this moment
the breakdown voltage of the compression stroke stage in the cylinder is very high
(>10,000V), and the breakdown voltage of the exhaust stroke stage in the cylinder is very low
(approx. 500V). The spark plugs in the 1-4 cylinders and 2-3 cylinders are directly connected
to the terminals of the secondary coils through high voltage cables.
Note: Take extreme care not to reverse the connection of high voltage cable during
reinstallation.
T-18