neon

Hi, I have a 1995 2.8 V6, it started running rough with lack of power when hot, now it's doing it when it's cold. I have looked at the MAF and it doesn't look damaged or dirty, but when I take off plug lead number 6 at the coilpack, nothing happens to the engine note at any revs. If I take any of the others off, it runs even worse, so I assume it isn't sending power from number 6 on the pack, but can anyone advise why or what to do. Thanks :)