The car won't start, when you leave it alone for 3 hours it starts again do you know what the problem is

On my gmc trk it was the ignition module,when the motor got hot it stopped and would not start once it cooled down it was fine till it got hot again.

you'll have to check for proper spark and fuel pressure when the problem occurs then make sure the injectors are firing

the GMC may have needed a good motor to chassis ground