What are the causes of engine failure to start?

[StBrantley]

Engine failure to start causes: Fuel supply system reasons: Low-pressure fuel line blockage, loose pipes causing fuel leakage, air in high-pressure fuel lines, poor technical condition of fuel injectors, incorrect fuel injection timing angle; Starting system reasons: Power supply failure, poor contact of electromagnetic switch, poor contact between starter motor commutator and brushes, clutch slippage in starter transmission mechanism; Insufficient cylinder compression pressure: Cylinder head gasket damage causing air leakage, valves not closing tightly leading to air leakage, and piston cylinder liner wear resulting in air leakage. Starter motor failure: Loose or detached starter motor wiring, switch or solenoid switch failure. Starter motors operate based on working principles including DC electric starters, gasoline starters, and compressed air starters. Most internal combustion engines use DC electric starters. If problems such as failure to operate or slow operation occur, proper inspection should be conducted.