Spark Advance Angle Control

In the Conventional EFI system, spark advance angle is determined by the position of the distributor (initial timing), position of the magnetic pickup reluctor teeth (centrifugal advance), and position of the breaker plate and pickup coil winding (vacuum advance). The spark advance curve is determined by the calibration of the centrifugal and vacuum advance springs.

Besides being subject to mechanical wear and mis-calibration, this type of spark advance calibration is very limited and inflexible when variations in coolant temperature and engine detonation characteristics are considered. Mechanical control of a spark curve is, at best, a compromise. In some cases the timing is optimal; in most cases it is not.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

Get My Free Ebook


Post a comment