fuel pump or line is bad on 1999 Kia Sportage

i ahve a 1999 kia that when it is ful run great but once the gauge goes near half tank it sputters and run badly can any one help

1 answer 1 comment
Definitely sounds like a fuel delivery problem, it could several things, but the fuel pump and fuel level indicator are certainly 2 places to inspect.

Any Check Engine Lights on?
no light are on , the only time the chk engine light come on when it miss firing an run badly , the machanic chage the fuel pump now he says it may be the fuel pump regulator that the only part they didnot change yet