I DRIVE A 1997 CHEVY TAHOE LE. ABOUT 2 WEEKS AGO I PUCHASED SOME GAS AND MY VECHILE START TO LURCH AND SHAKE REAL BAD AND AS TIME WENT ON IT GOT WORSE IT STOP AND WOULD NOT CRANK BACK AND WHEN IT DID IT WOULD NOT STAY RUNNING. SOME THE MECHAINC SWITHC SOME OF THED FUESES AROUND AND GOT IT CRANK . I INSTALL A NEW FUEL PUMP AND WHEN THE TRUCK IS IDLEING IT STILL SHAKES A LITTLE BIT AND ITS GOING DEAD COULD U TELL ME WHATS MAKE IT DO THAT.PLEAS HELP ME. I'M AT MY WITHS IN AND I THINK I'M BEING TAKING ADVANTAGE OF.