Chevrolet Repair: 88 chevrolet beretta, chevy beretta, chevrolet beretta

Question
i have an 88 chevy beretta that starts an runs good, until i get above 45 mph or it shifts into overdrive....it then begins to sputter an sounds like its missin....the timin is right..i put new coil packs on, new plugs, a new distributor, do you possibly know what this could be, because NO ONE that i have asked has ANY clue what it could be, can you help...i hope so!
~Phil

Answer
Could be several different things.
Youve covered some of them.
Try replacing the fuel filter.
A partially clogged fuel or air filter can make the same symptoms appear. You said it "sounds" like its missing, so it must be surging back and forth, correct?