the car wouldnt stay running and when it would shut off a puff of white smoke would come out the throttle body

 

you know a little more info than what you posted would probably get you a better response

this should probably be stickied somewhere but at the very least you need to post

year/make/model/mods/symptoms

that being said without any of the above info back fire out the intake I would take a look at my timing , both base mechanical and ignition, also make sure the firing order is correct