Originally Posted by Cashis EG8
Cap and rotor can really mess with the idle. Very cheap to replace but I would steer away from the pepboys/kragen/autozone branded ones - I got a set and had to replace it soon after with a Honda OEM cap and rotor.
I'm putting money on the fact that you have an aggresive race cam

*cough*ehemm*cough*
you must have a really aggressive cam