GuyLS400

so i bought a 93 LS400 for a great price a few weeks ago but it needed the starter,bought and replaced the starter and the car started but was very hesitant and the car was sort of jumping around.But then it was running fine. Theres a wire that comes out by the timing chain cover that rubed on the fan belt so i cut the wire spliced it back together started the car up and it was running fine but still hesitant, then a few days go by and while im driving the more i hit the gas pedal the more the car was bogging out (slowing down) became very hesitant. when i got home i replaced the plugs and it started up. when i started it up the car still had hesitation to hit when i gave it acceleration and then all of a sudden the car just ...turned off .so i thought it was the fuel pump but its not that! fuel pump is fine! Does anyone know what could be my problem??