Managment Of The Ignition - Fiat 1998 Marea Service Manual

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MANAGMENT OF THE IGNITION

The ignition management strategies are designed to strike the spark with the desired advance according to
the engine operating conditions.
The management of the ignition basically consists of determining the ignition advance and implementing it
through the operation of the power transistor incorporated in each coil.
The "basic" advance value, calculated according to the intake air flow rate and the engine speed, is then
corrected on the basis of the different engine operating conditions.
The control unit determines the moment of the start of the conduction of the current in the coil primary
winding according to the engine rotation speed.
The angle of this moment obviously varies, in relation to TDC for the explosion stroke of each cylinder
and, the greater the engine rotation speed, the greater the advance, because the (dwell) time required to
saturate the current in the coil primary winding is more or less constant.
The moment of the start of conduction is corrected according to the battery voltage.
1. System relay
2. Interface connector
3. Single ignition coil (pencil-coil)
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