What Causes a Hot Engine to Fail to Start?
1 Answers
Reasons: Engine carbon buildup, intake air temperature sensor, fuel quality, damaged carbon canister solenoid valve, fuel injector leakage, etc. 1. Fuel injector leakage: While fuel injectors normally spray fuel, leakage constitutes additional fuel supply. The more severe the leakage, the richer the air-fuel mixture becomes, making hot starts difficult. 2. Damaged carbon canister solenoid valve: During a hot start, fuel atomization is normally adequate without additional fuel vapor. If the carbon canister continues supplying vapor to the intake, it will over-enrich the mixture, causing starting difficulties. 3. Fuel quality: After a hot engine shutdown, the engine bay remains quite warm. If the fuel is highly volatile, it can create excessive vapor pressure in the fuel rail. When this pressure exceeds the fuel system pressure, vapor lock occurs, resulting in overly lean fuel vapor from the injectors and starting problems. 4. Intake air temperature sensor: Similar to the coolant temperature sensor, this sensor adjusts fuel injection. However, while a faulty coolant sensor causes cold-start issues, a faulty intake air temperature sensor leads to hot-start difficulties. 5. Engine carbon buildup: Carbon deposits strongly adsorb gasoline. Excessive carbon on intake valves, throttle bodies, or pistons can absorb fuel, creating an overly lean mixture that affects starting. This issue also occurs during cold starts.
