What Causes Low Idle Speed in Vehicles?

[LeMaci]

Here are the reasons for low idle speed in vehicles: 1. Oil accumulation and carbon deposits in the throttle body, or dirty intake passages: As the vehicle is used over time, the intake passages can become clogged. Carbon deposits or oil in the throttle body can cause unstable idle speed or even low idle speed. It is recommended that owners clean the throttle body and intake passages to avoid abnormal idle conditions. 2. Weak spark due to faulty spark plugs: Over time, spark plugs can also accumulate carbon deposits. When the deposits become severe, weak sparks from individual spark plugs can affect vehicle performance, leading to low idle speed. Timely cleaning or replacement of spark plugs is advised. 3. Fuel system blockages, such as clogged fuel injectors, or faulty intake pipes: When the fuel injectors are clogged, the vehicle may experience poor fuel pressure and inadequate fuel atomization, resulting in unstable or low idle speed. 4. Malfunctioning sensors: If the vehicle's sensors fail, the correct air-fuel ratio cannot be maintained. Common issues include faulty coolant temperature sensors, oxygen sensors, or throttle position sensors, leading to high fuel consumption and low idle speed.