Vernier pulley/idle question
 

Had the infamous top end intermittent chatter,I've had changed the solenoid and vernier pulley(sourced from salvo 60k car) the vernier pulley seems ok(as in the noise is gone) but the revs still go up and down slightly like it did before but now there is no chatter.I still obviously have some kind of problem,any ideas..does the ecu need reset.(the throttle body air valve was changed to).
Don't want to be back at square one and knacker the vernier pulley.
cheers, Colin

anyone help