Water in the gas?
Now if there is alot of gas/water mixture in the tank, I would remove the fuel filter and jump the fuel pump relay and pump it all out. DONOT let the pump run dry or it will burn up.
i would seriously drain it. if you let the car sit then it would be different. but someone else owned it before you. who knows, he could have put gas in it from a dirty gas can, or got stuff in there other ways. i would drain that beast and and then seafoam it.

