94 G STANG

WHATS UP GUYS I BOUGHT A 94 RECENTLY, AND IM FIXING IT UP. THE PROBLEM WITH THIS CAR IS WEIRD I CANT FIGURE IT OUT, WHEN I ACCELERATE PART THROTTLE EVERYTHING IS COOL, BUT WHEN I FLOOR IT- IT BACKFIRES AND DOESNT DO MUCH. THE CHECK ENGINE LIGHT COMES AND GOES AND SOMETIMES WHEN I FLOOR IT - IT TAKES OFF BUT KNOCKS REAL BAD LIKE THE TIMING IS TOO FAR ADVANCED. the fuel pressure is good, fuel filter is new as well as plugs and wires cap n rotor. Smells like its runnin rich. Has anyone come across something like this??? ans suggestions fellas thanks....................... oh ya sorry for the caps