1. you said "under the hood"
2. can you SEE anything moving? ( like the radiator fan )
3. if you can't see anything, is the smoke coming from the front of the engine ?
4. remove the engine cover ( pull up at the rear to unsnap from the hold-downs, then carefully at the front on both sides so as not to break the plastic. The whole thing will come off along with the 2 plastic intake pipes )
5. is the smoke coming from the round looking thing mounted on the front of the engine ?
6. If so, then you most likely have a stuck relay for the air injection fan in the RCM. - search for "Mystery No Start" to see about the RCM.