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.
Anti-AFTERBURN System: Operation
The anti-afterburn valve is sensitive only to sudden increases in vacuum. The length of time it stays open is controlled by a diaphragm that senses change in manifold vacuum.
When manifold vacuum suddenly increases, as during sudden deceleration, diaphragm/valve unit is pulled downward. Air flow from air chamber to sensing chamber is restricted by an orifice, creating a pressure differential on diaphragm, which holds valve open.
This unbalanced condition lasts for a few seconds until pressure in both chambers is equalized by air entering through orifice. When both chambers are equalized, spring pressure pushes diaphragm up, closing valve.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.