1988 Chevy Celebrity Car running rough

Hi guys, I have an 88 celeb, and it has 112,500 miles. Car has always ran great never any problems until now. The car starts fine, idles fine. The problem is during acc. I noticed there is a sputtering and the car sems to hesitate. Its a real rough ride. When I come to a stop it idles fine and sometimes on take it it sputters only for a second.I have noticed the problem being an issue from takeoff to about 50mph.I have recently replaced the fuel injectors, fuel filter and tested the pcv which was fine but replaced it anyway. The hose from the pcv is fine as well it doesn't collapse. The plugs look good no burning or rough edges.I don't see any prob with the wires but not sure when last time it had a tune up. If you guys could please help it would be great. Look forward to hearing from you.