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.
Coasting Valve
Connected to intake manifold, valve supplies fresh air from air cleaner to intake manifold to correct overrich mixture during deceleration. When coasting valve opens, intake manifold vacuum connected to vacuum chamber of air control valve is released to atmosphere. This shuts off air to air injection nozzles and directs it to the thermal reactor cooling circuit. The rise of intake manifold vacuum during deceleration and gear shifting causes valve to open, and air from air cleaner is directed to intake manifold to prevent afterburn. When engine speed exceeds 1400±50 RPM, control box energizes solenoid which opens vacuum line leading to vacuum chamber. Pressures in vacuum and air chambers are equalized and air from air cleaner overcomes spring force and flows into intake manifold. In addition, when coasting valve opens, vacuum chamber of air control valve is subjected to atmosphere and pressures in vacuum and air chambers are equalized allowing spring force to operate air cut valve.
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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