What Causes Engine Idle Shaking When Cold?

[MorganLynn]

There are 5 main reasons for engine idle shaking when cold: 1. Dirty air filter: The air filter is designed to protect the engine and reduce wear. Simply replace the air filter. 2. Broken high-voltage wire: A broken high-voltage wire refers to a break in the wire core, which can affect ignition and cause engine shaking. 3. Low idle speed: The engine idle speed is preset in the computer. When the RPM drops below a certain range, the car's computer will automatically adjust it. 4. Abnormal water temperature: The engine operating temperature has a normal range. High water temperature can cause early ignition timing, changes in the air-fuel mixture, thinning of engine oil viscosity, and reduced lubrication performance. 5. Clogged fuel injector: The fuel injector in an EFI car is a key component for fuel injection and has a long service life, reaching hundreds of thousands of kilometers. However, gum deposits in gasoline can clog the injector nozzles, causing inconsistent fuel injection among injectors, leading to uneven cylinder operation and engine shaking.