Idle Speed Regulating Valve

The idle speed regulating valve consists of 2 coils, fed voltage from fuel pump relay and grounds through the ECU. When ignition is turned on and engine is not running, ECU will ground one coil to open maximum air by-pass. When engine starts and speed increases, ECU grounds second coil while opening the first coil. By alternating ground control, ECU can adjust air by-pass to maintain proper idle speed. See Figure .