Wagoneer L6-258 4.2L VIN C 2-bbl (1982)
Thermal Vacuum Valve: Description and Operation
High Temperature Vacuum Signal Modulator
OPERATION
This unit is located at the rear of the engine compartment and is connected to the EGR vacuum signal hose. The modulator opens when the
underhood air temperature reaches 115° F and causes a weakened vacuum signal to the EGR valve. As a result, the amount of exhaust gas being
recirculated is decreased.
