What to Do When Experiencing Difficulty Starting a Hot Engine?
2 Answers
Here are the reasons for difficulty starting a hot engine: 1. Fuel injector leakage: Leakage constitutes additional fuel supply. The more severe the injector leakage, the richer the air-fuel mixture becomes, leading to difficulty starting a hot engine. 2. Damaged carbon canister solenoid valve: During hot starts, fuel atomization is normally sufficient without additional vapor supply. If the carbon canister continues to supply vapor to the intake tract, it will result in an overly rich mixture, making starting difficult. 3. Fuel quality: After a hot engine shuts down for a while, the high temperature in the engine compartment causes fuel to evaporate easily, forming high vapor pressure in the fuel rail. When this pressure exceeds the fuel system pressure, vapor lock occurs, causing the injector to spray overly lean fuel vapor and making starting difficult. 4. Intake air temperature sensor: Similar to the coolant temperature sensor, a faulty coolant temperature sensor causes cold-start difficulties, while a faulty intake air temperature sensor leads to hot-start problems. 5. Engine carbon deposits: Carbon deposits strongly adsorb gasoline. If there are significant carbon deposits on the intake valves, throttle body, or pistons, they can adsorb some fuel, resulting in an overly lean mixture and affecting starting. This issue can also occur during cold starts.
I know all too well about the difficulty of hot starts, a common issue with older cars. It's mostly caused by fuel system problems, like leaking fuel injectors that allow gasoline to seep into the cylinders after parking, resulting in an overly rich air-fuel mixture. It could also be due to aging ignition coils or spark plugs that can't provide sufficient spark energy at high temperatures. When I encountered this, I first checked for carbon buildup on the spark plugs, then pinched the fuel line to check if the fuel pressure was normal. If the engine compartment gets too hot, installing heat insulation padding can help. The key is to avoid forcing repeated starts, which can burn out the starter motor—it's better to let the car cool for half an hour before trying again. If all else fails, call a tow truck immediately. Last time I pushed my luck and ended up stranded halfway.
