Thermal Vacuum Switch (TVS)

Fig 41 Thermal Vacuum Switch:

PURPOSE
The thermal vacuum switch controls vacuum between the EGR CTO and EGR valve to improve cold engine driveability.

OPERATION
This switch is used on models with a 2 barrel carburetor. The switch functions as an on/off switch controlled by the air temperature of the air cleaner. At temperatures below 40° to 55° F, the thermal vacuum switch limits vacuum to the EGR valve.