How the idle speed control valve works
The speed control valve is powered by the ignition switch. As long as the ignition switch is turned to the ON position, the idle control valve is energized, and the engine computer controls its circuit grounding. When the operating parameters of the engine deviate from normal values, the valve is used to adjust the idle speed. The idle speed is adjusted by controlling the amount of air that bypasses the throttle body. After the engine is started, the idle speed control valve is opened for a period of time, and the engine speed is increased by about 150r/min-300r/min. When the engine coolant temperature is low, the idle speed control valve opens to achieve proper fast idle speed. The engine computer controls the position of the idle control valve plunger by varying the signal strength transmitted to the idle control valve based on the different coolant temperatures.
The stepping motor type idle speed control valve is one of the most widely used idle speed control devices in the world. It is used for the opening of the bypass air passage of the automobile EFI system, thereby adjusting the bypass ventilation to make the engine speed reach the required target value. Structural principle: a rotor composed of a permanent magnet, a stator composed of an exciting coil, and a feed screw and a valve that convert a rotary motion into a linear motion. It uses the step signal supplied by the system to perform the conversion control so that the rotor can be rotated forward or reversed, so that the spool (screw) can be telescopically moved to adjust the cross section of the bypass air passage, thereby stabilizing the idle speed, and The ideal idle speed is achieved.