i have an r33 and im getting weird idle probs also, the car was sometimes stalling becuase of extremely low revs but since yesterday it is idleing at around 1300 - 1400 rpm, with the occasional rpm spike, but will never drop below 1300rpm
im taking it to the local performance shop for a checkup, ill let you know what they find.
cheers
(if anyone has any ideas, let me know)!