loss of power.. miss

[nisan17]

In a previous post I needed to adjust clutch as I assumed my trouble was the clutch. Well, the adjustment improved the running a little.

The car still runs with a miss...there is a lack of power. I can go hwy speeds, but no passing power, but a gradual increase of speed. Again, I assume it was the plugs...checked same against a plug chart and they couldn't get any more normal(white appearence on all four) Wires, cap, rotor and plugs were changed 2 yrs ago this autumn. They still look good.

Any ideas?

Thanks in advance,