I own a 1996 Pontiac Bonneville that sat for 2 months because the water pump
was out. After it was fixed I had to charge Battery to get it to start
because it set for so long. Now I have a Fuel leak on the back of engine in
the center of the fuel rail behind vavle cover and coming from a black
looking vavle with a large vacum hose that's about a 3/8's in size and comes
from the firewall along with another hose of same size.

What is this Vavle? called and can I get it from my local parts store?
Oh! I did check the Fuel regulator and found no leaking fuel from vacum Hose!

Thank You!
Mike E.