Why does the vehicle idle speed suddenly increase?
1 Answers
Vehicle idle speed increases due to faults in the engine intake system and fuel system. Here are the relevant explanations: 1. In the engine intake system, components such as the throttle body assembly, air flow sensor, engine intake pipe, engine vacuum tube, and engine exhaust gas recirculation valve may be damaged. 2. Throttle body assembly: The throttle controls the air entering the engine, acting as a controllable valve. After the gas enters the intake pipe, it mixes with gasoline to form a combustible mixture, which then burns to generate power. Simply put, it functions similarly to a human throat. If this component fails and the throttle opening becomes uncontrolled, the throttle opening increases, causing the vehicle's idle speed to suddenly rise. 3. Air flow sensor: It converts the inhaled air flow into an electrical signal and sends it to the electronic control unit (ECU) as one of the basic signals for determining fuel injection. It is a sensor that measures the air flow entering the engine. If this component fails, the vehicle's ECU will inaccurately determine the amount of air entering the engine. Since the ECU cannot accurately judge the air intake, the vehicle may exhibit a sudden increase in idle speed. Engine vacuum tube: This component maintains the engine's vacuum level to ensure smooth operation. If the vacuum tube is damaged, the internal vacuum level of the engine becomes unstable. To maintain normal engine operation, the ECU will increase the engine speed, resulting in a sudden rise in the vehicle's idle speed.
