This does not happen every time but when accelerating (manual) I get a slight to moderate bucking as the RPM's go up. It almost feels like tapping the break while accelerating. Any ideas? Plugs and wires are not real old. Maybe the iginition coil? It does not feel like the clutch or transmission is slipping. Car idles pretty good and starts right up. Once I have it in 5th gear on the freeway with the cruise control on it seems fine. Only noticeable under acceleration.

Thanks,
Chris

how old are the cap and rotor?