What Causes Difficulty Starting a Hot Engine?
2 Answers
Reasons for difficulty starting a hot engine: 1. Carbon deposits: At high temperatures, carbon deposits have a strong adsorption effect on fuel. Excessive carbon buildup on pistons, throttle valves, and intake pipes can absorb part of the fuel, resulting in too much air and too little fuel, thereby affecting engine startup; 2. Faulty coolant temperature sensor and intake air temperature sensor: If these two sensors are damaged, they cannot provide correct temperature signals; 3. Fuel system failure: When the car is hot, the temperature is very high. If the owner opts for cheap, low-quality gasoline from small gas stations, it can cause gasoline to evaporate, resulting in an overly lean air-fuel mixture. Additionally, poor fuel pump operation or fuel injector leakage can also make it difficult to start.
I had a similar issue with my previous car where it often wouldn't start when hot. It's likely due to severe vaporization in the fuel system at high temperatures, causing uneven fuel injection and difficulty igniting. Another common reason is degraded performance of the ignition coils when hot, resulting in weak or no spark. It could also be the crankshaft position sensor falsely reporting error codes in hot conditions, causing the ECU to mistakenly prevent starting. When I dealt with it myself, I found the fuel pump was sticking when hot, and replacing it improved the situation. Additionally, an aging battery may not provide enough voltage in high temperatures, leading to weak starts. Next time this happens, I suggest turning off the AC and radio, waiting two to three minutes before trying again, or getting the battery and spark plug related components checked.
