B48 engine, why does the cold car start the engine slightly shaking?

Possible reasons: 1, the spark plug is not working well; 2. The vacuum tube leaks; 3, high-voltage line leakage; 4. The 4.PCV valve is blocked; 5. The throttle position sensor is faulty; 6, stepper motor idling fault; 7, idle speed control valve failure; 8. Abnormal throttle opening; 9. Air leakage in the air intake system. ?