Vacuum Regulator

1. Disconnect vacuum line from distributor port and connect a vacuum gauge.
2. With engine at idle, the vacuum gauge reading should be within 1 inch Hg vacuum of the calibration point. The calibration point of each valve can be identified according to color code as follows: Black, 6 inches Hg; green, 7 inches Hg; red, 8 inches Hg.
3. Replace valve if not within specifications.