I'm thinking its a vacuum hose but when i turn on my a/c or well anything that involves air blowing out of my panel vents.. it'll blow for a second then only the hi/floor. Any idea's.. I might have knocked something when i was putting new plugs on the "back" of the engine

Start with that. Alot of systems use some sort of vacuum canister under the hood to assist with the different vent positions.

but let me switch it up on ya.. when i stop the car suddenly.. it kicks on then when the car goes still off