BACK FIRE & HIGH IDLE

Hi, I was driving my 96' burban today and it was running fine. I put gas, then drove to the store. When I started it back up again to leave I heard what sounded like a backfire, and then it died on me. I waited a few minutes, then started it up again... it started fine, but now seems to be stuck at a high idle, and something smells burnt under the hood. Any suggestions on what it might be, so I know what I'm up against when I take it to a mechanic?


Thanks alot

Sounds like a vacuum leak of some kind