The reasons why hybrid car engines cannot start may include the following:
1. Insufficient battery power: Hybrid cars require power from the battery to start. If the battery power is below the minimum requirement, the vehicle will not be able to start. Battery aging, damage, or poor contact may also cause the vehicle to fail to start.
2. Electrical system failure: Problems with control units, relays, connectors, and other components in the electrical system may affect the normal starting of the vehicle. For example, faults in the throttle drive mechanism, lack of engine speed signal, and short start-up time may all be manifestations of electrical system failures.
3. Mechanical failure: Malfunctions in the internal mechanical parts of the engine, such as wear or damage to components such as pistons, connecting rods, and crankshafts, as well as insufficient fuel system pressure, may cause the engine to malfunction, thereby affecting the vehicle's start-up. Incorrect basic timing settings of the engine may also cause difficulties in starting.
4. Safety system failure: Hybrid vehicles are typically equipped with safety systems that prohibit starting the engine under specific conditions to protect the vehicle. If the security system malfunctions, it may also cause the vehicle to fail to start.
5. Environmental factors: Extreme environmental conditions, such as high temperature, low temperature, or high humidity, may affect the performance and starting ability of hybrid vehicles.
6. Other factors such as operational errors, oil quality issues, and failure to apply opening voltage to the protection switch may also cause the hybrid car engine to fail to start.
The above reasons are not all, the actual situation may be more complex. When encountering the problem of hybrid car engine not starting, it is recommended to contact professional car maintenance personnel for inspection and repair.