Ignition System: Description and Operation

Ignition System:

DESCRIPTION

The ignition system consists of a Single Board Engine Controller (SBEC), [1][2]crankshaft position sensor, cam position sensor, distributor, distributor cap, rotor, and a molded ignition coil pack.

OPERATION

The Single Board Engine Controller (SBEC) controls the ignition system. The SBEC controls ignition timing and coil dwell by controlling the ground path to the ignition coil. It has the capability of igniting the fuel mixture according to different engine operating conditions by delivering a variable electronic spark advance curve.

The SBEC has a built in microprocessor that continually receives input from the engine sensors. The SBEC then electronically advances or retards the ignition timing to provide good driveability during all operating conditions.

When engine is cold the SBEC will provide a set amount of advanced timing to assure a quick efficient start.

When engine is warm the amount of spark advance provided by the SBEC is determined by three input factors, coolant temperature, engine rpm, and manifold pressure.

The SBEC also receives information from the oxygen sensor and adjusts the air-fuel mixture to assure the most efficient fuel burn possible.

The SBEC also controls the Auto Shut-Down (ASD) Relay, which provides power to the ignition coil, fuel pump, oxygen sensor heater element, and fuel injectors.


NOTE: Only the components that affect primary and secondary ignition system operation are covered in this section. for more information on computer system and sensors see, COMPUTERS AND CONTROL SYSTEMS