15/10/2025
Common mistake when trying to regulate a car's RPM is to tune the engine without cleaning the idle valve. This means that, despite having a new air filter and new spark plugs, the vehicle still can't balance acceleration at idle, when braking, or when turning on the air conditioning:ππ
The idle valve is an actuator controlled by the ECU that regulates the amount of air entering the engine when the throttle is closed. Its main function is to maintain stable rpm at idle, compensating for the extra power consumption when the air conditioning, electric fan, or power steering is turned on. When it opens or closes, it allows more or less air into the intake manifold, ensuring the engine doesn't stall and runs smoothly at low RPMs.
There are several types of IACs:
Stepper motor: very common in older engines, it opens and closes in steps controlled by the ECU.
Solenoid (PWM pulses): Works with electrical impulses that move a needle proportionally.
Integrated into the electronic throttle body: In modern vehicles, it is no longer independent, but is managed directly by the electronic throttle's electric motor.
Regarding its removal and maintenance, it is normally secured to the throttle body with two screws. To remove it, first disconnect the electrical connector and then carefully remove the screws. The cavity where the valve operates accumulates soot and oil residue, so it is recommended to apply throttle body or injector cleaner spray to that area to remove dirt.
Important: Do not remove or manipulate the factory adjustment screw, as it regulates the needle seating and calibration, and if it moves, the engine may become overclocked or unstable.