Ignition System (Digifant II)

DIGIFANT II




Ignition System

The ignition system operates on the principle of a timing map programmed into the E.C.U. Information on engine load, speed and coolant temperature are provided to the E.C.U. in the form of voltage signals. In the E.C.U., these signals are processed so that the ignition coil is controlled via terminal 1 in accordance with the programmed ignition map.

An engine speed signal comes from the Hall sender in the distributor, and measurement of engine load is accomplished through a signal from the air sensor potentiometer. These two signals establish the ignition timing point. They are stored in the ignition map in the control unit's memory as 256 single operational points, 16 fixed points for each engine load point and 16 for each RPM point.

The engine coolant temperature sensor signals the control unit to correct the ignition timing based on engine temperature. Throughout the engine warm-up phase, ignition timing is constantly being corrected.

Once the engine reaches operating temperature, the timing is determined by the map shown.

Ignition timing is also corrected through the use of a knock sensor.