went out to get my truck out of the driveway and to the shop. didn't want to stay running and was missing again. kept firing up would shut off and started it up kept it running a little bit and smoke just started pouring out from under the hood ripped the hood open and there was smoke pouring out of the air cleaning got that off and it was white smoke out of the carb and a little bit out of the exhaust leak. what is that?