what would happen if you put oil mixed with sugar into the gas tank. it happened

Dont run the car! get gas tank REMOVED from car and thoroughly flushed including fill pipe assembly. Doing it with the tank in the car , although easier and less time consuming , will not be as effective(in my opinion- but I don't have to guarantee the job , nor do I need to worry about it 20,000 miles from now. In other words get a shop you trust to do a GOOD job , because odds are any residue that IS left , will take a while to show its' affects.