wont start on 2002 Pontiac Grand Am

I just got my 2002 pontiac grand am gt two weeks ago. It drove fine then three days ago i shut it off the next day wont start. I changed the fuel filter and camshaft sensor. The fuel pressure is reading 50 pounds. Im at a loss. Shot of ether it starts right up and will start all day when the engine is still warm but once it cools wont start again. Help?

1 answer
Check for the injector pulse with a voltmeter or testlight. I think the injectors are not working because of maybe a connector problem. Check for water or corrosion in the connector for the injector harness.
If you want to find a specialist, here's a directory link for you:
https://repairpal.com/directory?address=16858&car_brand_names=Pontiac