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° BTDC, but is retarded when the intake air temperature rises. When the temperature of the intake air has reached 100 °C the pre-ignition is 5° 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 the respective cylinder with 200 Hz for 60 crankshaft degrees, whereby a so-called multispark occurs. When the engine speed exceeds 450 rpm, the frequency will be increased to 330 Hz. The function is interrupted when the engine speed exceeds 650 rpm and is reactivated once the engine speed drops below 450 rpm.
This is to ensure ignition in unfavorable starting conditions and to prevent the engine from stalling directly after start.