Need help with strange underhood nosie
 

Okay so here is the deal I have just swapped a fresh longblock into my 95 4Runner and now when my truck is warmed up I am getting a strange noise which is coming from my Pair Valve. It is a buzzing sound and and seems to only happen when I am slowing down and the car is warm. I am pretty confident all the lines are hooked up correctly, though when I remove the vacumm line the sound pretty much dissappears. Do these things go bad often? Can I just dissconnect it and forget about it? Any help on fixing this prob would be appreciated. Thanks.