Ignition Timing Retard Unit

Check for loose, disconnected or deteriorated vacuum hoses and replace as necessary. Remove distributor cap and check that coupling rod is properly connected and that base-plate moves freely. Reinstall distributor cap. Connect a tachometer and timing light, start engine and check idle speed with engine at normal operating temperature and headlights ON. Disconnect vacuum hose from retard unit and connect a vacuum gauge to hose. Reading should be greater than 12 in. Hg. If reading is low, use compressed air to clear retarder port and recheck. If proper vacuum is still not available check engine tune-up condition. Set ignition timing to 5° ± 1° BTDC. Reconnect vacuum hose to retard unit and recheck ignition timing. Timing should be 0° ± 1°. If not, replace spark advance/retard unit and recheck.