Distributor Vacuum Control: Description and Operation

Vacuum Regulator:

A vacuum regulator is incorporated to give a better idle condition. The vacuum regulator is located under the rear area of the intake manifold. The lower port of vacuum regulator, marked CARB, is sourced to throttle butterfly. During idle conditions, the vacuum regulator limits vacuum signal available for vacuum advance unit to 11.0 in ± 1 in Hg (9.372 ± .033 bar)