Idls/Reving Problems

Sup guys. I have a crazy(to me) issue. The other day the car started to die when it idled down. It sat for two days then it ran fine. Two days ago it started doing that again. We changed the plugs to no avail. Heres the strange part. This one relay, when you take it out it cranks and idles rough. You cant rev it, when you press the gas it barely gets to 1K rpms. If you put it in the same thing happens(while running). If you put it back in and crank it back up it wont stay running. It turns over then dies. But if you crank and press the gas, it runs and revs all the way like it should unless you let off, and then it dies. The relay in question is not in this pic...LOL...but it goes in the spot where the three are lined up vertical. there are the three in the pic, then skip a slot and then the one Im talking about is there. I cant find what it is for anywhere. The diagram doesnt tell me anything, its just an engine.

any help on what this relay is, or what my issue could be please let me know...


heres the pic...

http://i264.photobucket.com/albums/i...0130001449.jpg