Beater car

Hi guys, I just bought a 96 oldsmobile cutlass ciera with the 3.1, and it has a problem.  It has about 156000 miles.  When I am trying to accelerate, it does just fine on take off but as soon as I get over 15mph it starts to hesitate really bad.  It will pick up speed just as fast if I berely have my foot on the pedal compared to 3/4 throttle.  Thats when I floor it and it does just fine.  It seems at low rpm it has no power.  I know nothing about cars, just my truck and I am confused as hell.  Thanks guys

    Have your fuel pressure checked, and look to see if it has coil -packs, if it has coil packs they are probably bad. if it has a distributor it might need attention too.

check fuel pump and filter and injectors

Thanks for the help guys.