Why does the engine shake during cold start?

[OEliza]

The reasons for engine shaking during cold start are: 1. Low ignition energy at low engine temperature; 2. Inappropriate air-fuel mixture ratio; 3. Carbon buildup on valves and intake ports; 4. Uneven cylinder performance; 5. Ignition system malfunction; 6. Aging engine mounts. Solutions for engine shaking during cold start include: 1. Clean fuel system and check for carbon buildup in idle control valve; 2. Inspect spark plugs for excessive carbon deposits and replace if necessary; 3. Check fuel pressure and replace components when needed; 4. Verify battery voltage is within specified range. The steps for starting a car are: 1. Press brake with right foot and clutch with left foot; 2. Shift to neutral and turn key to start; 3. Keep both feet on brake and clutch, shift to first gear and release handbrake; 4. Release brake and clutch, then press accelerator with right foot to start moving.