Transmission Kickdown Switch
The Transmission Kickdown Switch is a sensor— mounted on the throttle body—that signals the transmission to downshift when you press the accelerator pedal hard. When you push the accelerator past a preset point (indicating you need rapid acceleration), the kickdown switch is activated. It sends a signal directly to the transmission, prompting it to shift into a lower gear. This “kickdown” increases engine RPM and torque, giving you more power when you need it.
This part is somewhat difficult to find as reproductions are not available.
Vacuum Advance
A vacuum advance adjusts the ignition timing based on engine load. When the engine vacuum is high—typically during light loads like cruising—it advances the spark timing, which improves fuel efficiency and performance. Conversely, under heavy load or low vacuum, it retards the timing to prevent knocking. This automatic adjustment helps optimize combustion across various operating conditions. It it located/connected to the distributor.
Choke Stove Tubes
Located next to the carburetor, the choke stove tube directs warm air to the choke mechanism, which is a metal spring. As the engine warms, the hot air causes the spring to expand (and lose some tension), which allows the choke to open gradually. This transition helps shift the fuel mixture from a richer, cold-start setting to a leaner mixture for normal operation.
PCV Valve and Grommet
I replaced the PCV valve and grommet—an essential part of the emissions-reducing system that recycles air from the intake to the exhaust. Unfortunately, the brittle rubber grommet broke off and fell into the intake, disappearing from view. Thankfully, armed with a small scope and retrieval claw, I was able to locate and remove it before it caused any damage.
Exhaust Manifold Dressing
I used Calx Dressing to refresh my rusted exhaust. The product is quick and easy to apply with a toothbrush, and though it needs occasional reapplication, it’s far simpler than trying to repaint the manifold while it’s still in the car.
