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.
Deceleration Control System - CALIF: Description
The Deceleration Control system is designed to maintain a balanced air/fuel mixture during deceleration. Upon initial deceleration, rapid closing of throttle plates can cause overly rich fuel mixture.
This system consists of air by-pass valve on California vehicles and throttle positioner system. The throttle positioner system consists of servo diaphragm, engine speed switch and 3-way solenoid valve. California vehicles also use a throttle dash pot in addition to the throttle positioner.
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.
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