LN7 L4-98 1.6L SOHC VIN 4 2-bbl HP (1983)
Air Injection Control Valve: Description and Operation
Thermactor Vacuum Vent Valve
Fig. 65 Thermactor vacuum vent valve
Fig. 66 Thermactor vacuum vent valve schematic (typical)
This valve, Figs. 65 and 66, is used on some engines equipped with variable venturi carburetor. It provides the air for the thermactor retard delay
valve and air bypass valve during idle modes to deactivate the thermactor system after a controlled period of time. Application of vacuum from the
carburetor to both ports of the thermactor vacuum vent causes the dump valve to seat and vacuum to be applied to the rest of the system. Removal of
vacuum during idle modes results in unseating of the dump valve, opening of the vent and allowing air to enter the system to reduce the vacuum
previously applied to the retard delay valve.