What Causes Engine Shaking During Cold Starts?
1 Answers
Engine shaking during cold starts can be caused by: 1. Excessive carbon buildup in the throttle body, fuel injectors, or intake passages; 2. When there's too much carbon deposit inside the engine, the gasoline sprayed by cold start injectors gets largely absorbed by the deposits, resulting in an over-lean air-fuel mixture that causes startup vibration; 3. Cylinder misfire due to mechanical failures in ignition coils, spark plugs, or fuel injectors; 4. Insufficient power caused by low fuel pressure or cylinder compression; 5. Substandard fuel quality; 6. Damaged or excessively dirty idle control valve; 7. Intake manifold air leaks; 8. Damaged engine mounts or cushion pads; 9. Oxidized or low-grade engine oil with poor low-temperature fluidity, leading to inadequate cold-start protection for the engine.