Feedback Carburetor System: Description
The feedback carburetor system maintains the proper air/fuel ratio during engine operation. Air control valves are used to by-pass additional air into the intake manifold to adjust a temporarily rich mixture condition. The system consists of 2 feedback systems, the "X" and "M" systems.
The "M" system consists of a check valve A (Civic 1500), air control valve A, frequency solenoid valve A and the control unit.