Nex ive got a couple of ferrite rings on the whole lot now (as far as i can tell theyre doing no good -- will probs try them in another location tomorrow) all the wiring connections are in the interior and soldered...ive been through out the engine bay and nothings obviously loose...tbh Nex with the nismo mounts the engine dont move any more
yea i have never found any good from ferrite rings but worth a try,
the nismo mounts sound awesome
what happens if you disconnect the RPM signal completly? does the engine still idle?
the dizzy has an optical sensor doesn't it? try checking how that is working, if it is clean or something, maybe there is something triggering the photosensor like a flash from a spark in the dizzy. not sure what it could be tho