9-5 Linear (9600) L4-2.3L Turbo (2.3t) (2004)
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Ignition Timing: Description and Operation
Starting Ignition Timing
Starting Ignition Timing
Starting ignition timing is active from the point when the engine starts until the engine speed has reached the requested idling speed.
Ignition timing is normally approx. 8 degree BTDC, but is retarded when the intake air temperature rises. When the temperature of the intake air has
reached 100 degree C the pre-ignition is 5 degree BTDC. The reason that the ignition is retarded when the air temperature rises is that the combustion
velocity also rises.
When starting, the control module triggers each cylinder with a 200 Hz signal for 60 crankshaft degrees, whereby a so-called multi-spark occurs. When
the engine speed exceeds 450 rpm, the frequency will be increased to 330 Hz. The function ceases when the engine speed exceeds 650 rpm. If the
engine speed drops below 450 rpm again, the function will be restarted provided the coolant temperature is below -10 degree C.
This is to ensure ignition in unfavourable starting conditions and to prevent the engine from stalling directly after start.
