Hey Boys I got r33 skyline GTST series 2 rb25det yesterday and today suddenly the revs not revs on speedo but the revs in engine go up and down on idle, from 1100rpm to 1300/1400rpm, drives normal still boost no smoke no stalling nothing else just idle up n down sounds like lumpy cam, it has apexi power fc handheld, can anyone help me please? Or give me idea of what problem might be?
Appreciate it guys
Thanks
DK