What Causes Unstable Idling and Car Shaking?

[LeNova]

There are several main reasons for unstable idling and shaking in cars: 1. Improper air-fuel mixture: The incorrect ratio of air to fuel in the engine compartment leads to ECU miscalculations, causing errors in the control of the air-fuel mixture and ignition timing through actuators. This reduces the vehicle's power output, resulting in shaking. 2. Low ignition energy: The primary issue during cold starts is low temperature. Insufficient engine, fuel, and lubricant temperatures require more fuel injection during cold starts to meet power demands. 3. Carbon deposits on valves and intake passages: Carbon buildup on engine valves and intake passages also fails to meet the vehicle's power requirements, leading to unstable idling and shaking.