The car is not starting only when the engine is very hot.
Possible Cause why the Car will not start when the Engine is Very HotSolenoid is Too Hot
When car does not start if the engine is hot the possible cause is a solenoid that is too hot. When the engine is extremely hot the heat coming from the engine will radiates outward into all other components which include the solenoid. The solenoid functions as a switch that turns on the starter when the ignition key is turn on. When the solenoid becomes too hot it will fail to function, as a result the engine will not start.
Free Car Diagnostic Recommendation
When you encounter this kind of problem you cannot do anything but to wait until the engine cools down including the solenoid, and then start the engine again. If the problem will occur continually try installing a heat shield around the solenoid in this case it will prevent the heat coming from the engine to radiate into the solenoid which also prevent the solenoid from getting too hot especially during summer when the temperature of the surroundings is extremely high.