1994 pontiac grand prix gtp 3.4 v6 idle problems?

I've noticed when I just barley touch the gas my idle goes up from 800 rpm's to 11 or 1200 rpm's and stayes there for about 3-4 seconds then goes back down. I decided to check if it was a vacuum leak, I heard a hissing sound between the power steering pump and the intake manifold, I sprayed throttle body cleaner to see if the idle would drop and it seemed like it did. so I replaced the intake manifold gaskets and some hoses. I figured I fixed the problem and started the car. I didn't fix the problem... I just cant figure out the problem. I don't see any hoses by where the hissing is coming from. I seems like the noise is the power steering pump pulley but its sounds like the hissing is right behind it.. can the idle problem be something else..