Weird hissing from between intakes??

So I recently installed new e-v6 39lb injectors in my car to go with my supercharger setup before getting it tuned and I keep hearing this odd hissing sound like a vacum leak that is coming from between my cobra upper and lower intake manifold. So I have taken the manifold off about 3 times and looked for vacum leaks; everything seems fine also have sprayed 2+2 around looking for leaks and have not come up with any. The hissing sound is coming from the driver side between the intakes and I almost feel that it is coming from the last fuel injector on that side, but its not leaking any fuel nor can I feel any air coming from it when the car is running. The funny part is that I can barely hear it when the car is just ideling, but if I put my hand between the intakes the hissing becomes more noticeable and louder. I have pulled, wiggled, listened, and listened some more and I can't figure out what it is. The only thing I can think of is maybe its the fuel injector that is hissing, if so how can I fix it??