Will not start once the engine has warmed up

Hello,

It issue could be caused by a faulty coolant temperature sensor.
The coolant temperature sensor changes internal resistance with temperature. It can malfunction and send incorrect data to the ECM and the engine is 'too hot', in turn the ECM will not allow the engine to start. But after it cools down some you are able to start it.

That sensor can be tested using a multimeter by checking for resistance.

Here are some helpful articles:

https://www.2carpros.com/articles/how-a-coolant-temperature-sensor-works
https://www.2carpros.com/articles/symptoms-of-a-bad-coolant-temperature-sensor

I have attached the coolant temperature sensor testing procedure below.

Please let me know what you find.
Thank you.