Distributor Ignition (DI) System

Distributor Ignition System:

PURPOSE
The ignition timing is controlled by the ECCS Control Module (ECM) to help maintain the best blend of engine performance and emissions under all operating conditions.

Ignition Map:

OPERATION
The ignition timing data is stored in the ECM located in the ECM, in the form of the map shown in image.
The ECM detects information such as the injection pulse width and crankshaft position sensor signal which varies every moment. Then responding to this information, ignition signals are transmitted to the power transistor. e.g. N: 1,800 rpm, Tp: 1.50 msec A B.T.D.C.
In addition to this,
1) At starting
2) During warm-up
3) At idle
4) At acceleration
5) Hot-engine operation
The ignition timing is revised by the ECM according to the other data stored in the ECM.
The retard system by knock sensor is designed only for emergencies. The basic ignition timing is pre-programmed within the anti-knocking zone, even if recommended fuel is used under dry conditions. Consequently, the retard system does not operate under normal driving conditions.
However, if engine knocking occurs, the knock sensor monitors the condition and the signal is transmitted to the ECM (ECCS control module). After receiving it, the ECM retards the ignition timing to avoid the knocking condition.