Idle Speed Control

Idle speed stabilizer is separate from digital control unit. The throttle switch is used to initiate idle speed control. Air control valve, located in throttle valve by-pass hose, receives signals from idle speed stabilizer.

With ignition on and engine off, air control valve is activated. This provides a valve opening which is determined by coolant temperature. After engine is started, idle stabilizer adjusts idle speed based on idle stabilizer thermo switch, throttle position, and engine RPM.

A/C operation will also send a signal to the ECU which will modify the signal to the air control valve. Engine speed is controlled by temperature from 1000 RPM at 0°F (-20°C) to low of 720 RPM at 68°F (20°C).