780 V6-2849cc 2.8L SOHC B280F (1987)
Three-Dimensional Ignition Map
TIMING PROGRAM:
The control unit is programmed with a series of specific settings for a number of defined speeds and engine loads. These settings are stored in the ECU
as an "ignition map". This means the timing can be controlled to the accuracy of a fraction of a degree. The ignition ECU will adjust the timing
according to this "ignition map" at all times under all engine loads (except engine knock).
ANTI-KNOCK PROGRAM:
Knock causes high and dangerous combustion temperatures. The ignition system will retard the timing in approx. 3° increments (to a maximum of 15°)
to reduce knock.
When the knock problem has been eliminated, the ignition ECU will advance the timing in 0.37° steps until the normal setting has been restored or
knock reoccurs.
RPM LIMITER PROGRAM:
At approx. 6300 RPM the ignition is interrupted to keep the engine from overrevving.
STANDING CURRENT PROTECTION FUNCTION:
To avoid overheating the coil when the ignition is ON and the engine off, a separate circuit interrupts the current to the coil. The ECU uses the engine
speed and position signal to determine if the engine is running or at rest.
