revving and holding at 3000 revs

hi guys and girls, i have a vauxhall frontera 3.2 v6 (or known as a Honda passport, 6VD1) i have changed the idle control valve for a new one, and its still doing the same, when i remove the idc from the throttle body, and switch the ignition on then of, it resets its self right back, leaving the idc in the fully open position, this also does it when in the throttle body, i have check all vacuum pipes and replaced nearly all of them,, what else am i looking for, cheers andy