What Causes Engine Failure to Start When Hot?

[StAvery]

There are several reasons why an engine may fail to start when hot: 1. Carbon buildup in the vehicle causing ignition difficulties, accompanied by slight vibrations at idle. Cleaning the throttle body, intake manifold carbon deposits, and fuel injectors can resolve this issue; 2. Long-term failure to replace spark plugs, leading to severely reduced spark energy and misfires. Many current engine models use direct fuel injection, which places higher demands on spark plugs; 3. Insufficient fuel rail low-pressure supply. Low fuel pressure in the low-pressure fuel line directly causes the engine to require a second ignition attempt. The specific reason is that the first attempt fails as the low-pressure fuel line is building up pressure, while the second attempt succeeds.