Just figured id put this out there for anyone who cant figure out their ac, iv done this after checking EVERYTHING i could on this site to no avail so im not saying this will fix your in specific but its a nice thing to check quickly (easier than looking at EVERY ac vaccume line for hours in the 100+ weather at least like i had to)

so out of your fire wall there are two vaccume hoses, one gos to your...uhm emmision thingy haha, idk what its called but its that plastic thing connected to all the hoses on your passenger side. now the second one gos and connects to this the way plastic thing that connects to your intake (for vaccume i assume) and then the other hose gos alllll the way to driver side front of your car to some cylendrical thing, well my plastic thing was broken thus it had no vaccume! so what i did was take off the plastic peice and just shove both hoses in there, the big one where the plastic peice was and the small one i used a razor and cut a hole just big enough for the small hose to go in the side of the hose, altho i had to use some hose i found in my grauge to extent the smaller hose to make it there. and it worked! and it probably will help my engin to sense now i dont have a vaccume leak and pretty much and open hole in my intake.

hope this helps someone