Vacuum Regulator
TWO PORT TYPE
1. Connect a suitable vacuum gauge to vacuum regulator output port.
2. With engine at idle speed and manifold vacuum at input port, vacuum gauge should read 10.5 to 13.5 inches Hg. of vacuum.
3. If gauge reading is not within specifications, replace vacuum regulator.
THREE & FOUR PORT TYPES
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.