Spechul ed

So I changed my fuel pressure regulator after trying to diagnose a hard starting problem, and I also changed the fpr vacuum line as well. I have not done a fuel pressure test. But upon a cold start the fuel pressure regulator makes a chattering sound.before I pulled the fpr, I did not pull the pump relay and let it run and die, and I did not push the Schrader valve in to release the pressure either. Upon in stall I used some Vaseline to lube the o rings for easier install. I cycled the key 3 or more times before I started it, now the fpr is noisy fpr about 10 minutes at a idle when I pull up to a stop sign or stop light then by the time I get to work by driving on the freeway the sound is gone. What is going on. Please help.