1998 Buick Century fuel pump

1998 Buick Century 4 cyl Automatic 180000 miles

i just leased a 1998 buick century. Had it about 2 weeks now. When I test drove it was as quiet as a whistle but sometimes it took multiple cranks to get it started. So they replace the fuel pump and filter. Sometimes when I crank up the car it vibrates and you can here the pump pumping but if you shift into gear before it stops making that pumping noise the car cuts off. Now its making a humming noise whenever you turn the wheel. What could this or why could this be?