05 century hard start

I have a 2005 century with 130k miles. When the car has not been started for a while it has a hard time starting. Once it starts if i shut it off it then restarts even if the engine is stil cold.if I give it some gas even a drop it starts up. Idle is smooth and no problems while I am driving.

This sounds like you may have a leaking injector that is causing the fuel pressure to drop below an acceptable level when the car sits for a while. The next time you let the car sit turn the key on and wait until you hear the fuel pump stop making a noise and then try to start it. If the problem continues you should have the fuel pressure regulator and the injectors checked.

I dont understand what can be bad about a fpr? I dont smell any gas when i remove the vacuum line and it is just a diaphragm. Also the pressure seems to be right. I have not been able to test it when it does it since it is very intermittent and i dont own a fuel pressure tester.
Also is there anyplace I can find a list of steps to test the vacuum hoses? I own a gm service disk but it does not seem to have it.