What is the working principle of an automobile idle speed motor?
2 Answers
Working principle of an automobile idle speed motor: The electromagnetic valve controlled by the computer ensures the stable operation of the engine. The computer reads various data from the engine, processes the information, and transmits the data to the idle speed motor to achieve engine stability. The internal structure of the idle speed motor consists of three parts: the rotor, stator, and threaded transmission mechanism. The stator is composed of two sets of coils, while the rotor is made of a permanent magnet with two magnetic poles. The idle speed motor is installed on the automobile throttle body. It adjusts the area of the idle speed air hole through a stepper motor, thereby controlling the intake air volume of the engine's intake pipe. Subsequently, the intake pressure sensor sends the detected intake pressure to the computer, which determines the intake air volume or engine load and calculates the required fuel injection amount to control the engine's idle speed power.
In my previous auto repair work, I encountered quite a few idle speed control valve issues. It's essentially like a little electronic helper that keeps the engine running at a steady RPM when the vehicle is stationary. The principle is quite simple: when the car idles, such as at a red light, the computer (ECU) controls this motor to open and close the valve, adjusting the air intake. Why? Because factors like engine temperature, AC activation, or braking affect demand – the ECU receives sensor signals and commands the motor to act, ensuring the proper air-fuel mixture ratio to stabilize RPM. If it gets stuck or accumulates too much carbon buildup, the RPM will fluctuate or even cause stalling, which makes driving uncomfortable and increases fuel consumption. I've noticed car owners find this issue particularly annoying. My advice is to regularly clean components around the throttle body to prevent malfunctions, otherwise repairs might require costly part replacements. Understanding how it works ultimately helps us drive more comfortably.
