What Causes Difficulty in Starting a Hot Engine?

[McBeckett]

Difficulty in starting a hot engine may be caused by fuel injector leakage, a damaged carbon canister purge valve, or fuel quality issues. Below are the reasons and solutions for difficulty in starting a hot engine: 1. Fuel injector leakage: While fuel injection is normal, leakage results in additional fuel supply. The more severe the leakage, the richer the air-fuel mixture becomes, leading to difficulty in starting the hot engine. 2. Damaged carbon canister purge valve: During a hot start, fuel atomization is already normal and does not require additional fuel vapor. If the carbon canister continues to supply fuel vapor to the intake manifold, it will cause an overly rich mixture, making it difficult to start. 3. Fuel quality: After the hot engine is turned off, the engine compartment remains at a high temperature. If the fuel is highly volatile, it can form high vapor pressure in the fuel rail. When this pressure exceeds the fuel system's pressure, vapor lock occurs, resulting in overly lean fuel vapor from the injector and difficulty in starting.