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.
CALIFORNIA Models
One circuit of system is connected to vacuum at the throttle port, the other at intake manifold. When the throttle plate suddenly closes, creating more than 10.6 in. Hg, the check valve closes. Vacuum pulls the throttle opener and it holds the throttle plate open. Vacuum drops slowly as the delay valve bleeds it off.
When vacuum drops too low, the check valve opens. Intake manifold vacuum is applied and controlled by vacuum regulator at 6 in. Hg. This vacuum keeps the throttle plate positioner half-open. When vehicle speed drops below 17 mph, the speed sensor turns off the solenoid valve. Manifold vacuum is cut off and the throttle closes.
A separate dashpot (not vacuum controlled) keeps the throttle from closing completely for 2-4 seconds.
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.