What Causes a Car to Have No Idle Speed?
2 Answers
Reasons for a car having no idle speed: 1. Low car battery voltage; Specific detection method: Use a multimeter voltage range to test the battery voltage. If it's below 10V, replacement is recommended. If it's around 11V, it can barely be used; be prepared for replacement. Above 12V is usable. 2. Check if it's caused by carbon deposits; if the car has run about 20,000 KM, focus on inspecting and cleaning the throttle body. 3. Inspect, test, and replace the spark plugs. 4. The control unit receives incorrect signals and issues wrong commands, leading to inaccurate control of the engine idle air intake, causing abnormal engine combustion. 5. Faulty idle air actuator resulting in inaccurate idle air control.
My car previously experienced an idle speed issue, with common causes including excessive carbon buildup in the idle control valve causing it to stick, or a dirty throttle body affecting airflow. Another possibility is a faulty sensor, such as a malfunctioning mass airflow sensor, where the signal fails to reach the ECU, leading to unstable idle. I recall during one inspection finding that a loose ignition coil could also cause similar problems—the car would stall after starting and shifting gears, which was quite troublesome. For a preliminary self-check, you can try cleaning oil residue around the idle valve, but it's best to avoid blind tinkering to prevent mistakes. Safety is key: without proper idle, the car is prone to stalling during low-speed turns, increasing accident risks, so I always recommend going to a professional repair shop promptly. Regular maintenance like carbon cleaning can effectively prevent such issues—don’t wait until a major problem arises. Additionally, owners of older models should be extra cautious, as idle problems often stem from multiple compounding factors. Don’t underestimate it, or repair costs will only escalate.
