Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
6-CYL. & V8 Engines
Thermal vacuum switch is a normally closed switch which is sensitive to oil (6-Cyl.) or coolant (V8) temperature. With a cold engine, below 105°F (40°C), TVS is closed which allows manifold vacuum to actuator valve. Vacuum pulls diaphragm in actuator, closing EFE Valve.
This causes hot exhaust gases to be routed to base of carburetor. When engine temperature is above 105°F (40°C), thermal vacuum switch opens. This stops vacuum to actuator. Without vacuum, spring pushes actuator diaphragm to its at rest position and opens EFE valve.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.