Vacuum Transducer

The vacuum transducer provides an intake manifold vacuum signal to the Spark Control Computer. The higher the vacuum, the more spark advance that is given. To obtain the greatest amount of advance for any inch of vacuum, the carburetor switch must be open for a specified time. The advance at this time happens slowly. If the carburetor switch closes, the advance is cancelled, but the computer puts the last point of advance in memory; then the advance slowly drops to zero. If the carburetor switch is opened before the advance drops to zero, the advance at point of memory, is restored. If zero advance is reached, the advance must start from zero.