I changed the transmission on my sl2 put everything back the way it came off and now the engine will start but it idles rough for a couple seconds than goes to normal idle for a couple seconds and than dies, if you push the throttle it dies immediately?

 

Stop in the new member area and give yourself a proper introduction. While your at it go to the USER CP, open signature and add your first name, location, and car info.

 

That sounds like mabe a vacuum leak. Do you hear a hissing sound from under the hood when it is running

 

Make sure you didn't pinch a vacuum line or wire between the bell housing and block when you put it back together.