Runs great starts most of the time but randomly will crank but no start

try replacing the fuel pump relay, and when u know the vehicle is going to have issue starting, rent a fuel pressure tester, check fuel pressure. sounds like fuel pump is bleeding off pressure overnight, or when its been sitting a few hours. try turning on the key, but dont start engine, then turn off. do that 3-5times, then try starting the engine. if it starts easier, most likely its a weak fuel pump