What Causes Difficulty Starting After Warming Up the Engine?
1 Answers
Reasons for difficulty starting after warming up the engine: 1. Fuel injector leakage: While fuel injection is normal, leakage constitutes additional fuel supply. The more severe the injector leakage, the richer the air-fuel mixture becomes, leading to hard starts when the engine is warm. 2. Damaged carbon canister purge valve: During warm starts, fuel atomization is already normal and doesn't require additional fuel vapor. If the carbon canister continues supplying vapor to the intake, it creates an overly rich mixture, making starting difficult. 3. Fuel quality: After shutting off a warm engine, the engine compartment remains hot. If the fuel is highly volatile, it can form excessive vapor pressure in the fuel rail. When this pressure exceeds the fuel system pressure, vapor lock occurs, causing overly lean fuel vapor injection 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 warm start difficulties. 5. Engine carbon deposits: Carbon buildup strongly absorbs gasoline. Excessive carbon on intake valves, throttle bodies, or pistons can absorb fuel, creating an overly lean mixture that affects starting. This issue can also occur during cold starts.
