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.
Feedback Carburetor System: Description
The feedback carburetor system maintains proper air/fuel ratio during engine operation. Air control valves are used to bypass additional air into the intake manifold to adjust temporary rich mixture condition. The system consists of 2 feedback systems, "X" and "M".
The "X" system consists of an air control valve B, air chamber (Accord), feedback control solenoid valve (Accord and Prelude), frequency solenoid B, constant vacuum valve (Prelude), constant vacuum generator (Accord), check valves A, B, C and E, surge tanks A and B, vacuum switch A (Accord) and the control unit. Surge tank A is used as a reservoir. Surge tank B is used to dampen vacuum pulses to air control valve B.
The "M" system consists of check valve A (Civic 1500 and Prelude), air control valve A, frequency solenoid valve A and the control unit.
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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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