What Causes the Idle Speed to Fluctuate After Cleaning the Throttle Body?
1 Answers
Because the throttle opening has not been reset. Due to long-term carbon buildup, the throttle body gets squeezed by the carbon deposits, causing the throttle opening to expand. After cleaning the throttle body, if it is not reset, the throttle opening will remain in the pre-cleaning state, leading to increased air intake. In severe cases, this can result in unstable idle speed. Below are the methods to reset the throttle opening: 1. Most modern cars use electronic throttle bodies, which require a diagnostic tool to match the computer and perform throttle initialization to achieve normal idle speed. Some older models still use mechanical cable-operated throttle bodies, and these vehicles will gradually restore the throttle opening to its initialized state during subsequent driving, naturally stabilizing the idle speed. 2. For example, before cleaning the throttle body, disconnect the negative terminal of the battery, or after cleaning, turn the key to the ON position and wait for a few minutes before turning it off. Then, turn it to the ON position again, press the accelerator pedal fully without starting the engine, and then start the car. Some car owners report this method works, while others find it ineffective. In fact, reset methods vary by car model, and the quickest way is to use a computer for matching.
