What are the main causes of difficulty in starting a hot engine?

[Vickie]

The main causes of difficulty in starting a hot engine are: 1. Fuel injector dripping; 2. Engine carbon buildup; 3. Poor fuel quality; 4. Intake air temperature sensor issues; 5. Damaged carbon canister solenoid valve; 6. Spark plug failure; 7. Idle control valve malfunction; 8. Coolant temperature sensor failure. The coolant temperature sensor is a crucial sensor for the car's starting signal. If the coolant temperature sensor fails when the engine is hot, it cannot provide accurate feedback to the engine ECU. As a result, the engine ECU cannot determine whether the engine is cold or hot, leading to inaccurate fuel injection pulse width during startup.