Idle Feedback System

1987-88 Accord
The idle feedback control system consists of air bleed valve B, located in the air cleaner, and an air leak solenoid valve. The air bleed valve responds to intake air temperature, and the valve opens as air temperature increases. The air leak solenoid valve is controlled by the control unit, and allows additional air to be drawn into the intake manifold. The air leak solenoid valve is opened when the engine is running at idle, and when intake air temperatures are high enough to open bleed valve B, additional air is drawn into the manifold.



1987 Prelude
The idle feedback system uses an air leak solenoid valve and an air cleaner mounted thermovalve to direct air into the carburetor primary slow circuit. Additional air is provided to the primary slow jet during idle when air injection into the exhaust stream is cut-off. As the engine warms up thermovalve C opens and allows air to flow to the air leak solenoid valve. The air leak solenoid valve is operated by the electronic control unit based on signals from the ignition coil (engine speed), vacuum switch C (carburetor vacuum) and oxygen sensor. When the control unit senses that idle mixtures are excessively rich, the air leak solenoid valve is energized and additional air is drawn into the primary metering circuit.