Join Date: Jan 2006
Location: Alexandra, New Zealand
When checking the IACV did you check and adjust the TPS according to BGB? Can do this with t on bench or installed to make sure the throttle position clearances are correct according to TPS resistance. Best to also make sure internal butterfly is not sticky as often a lip of debris is formed in TB which prevents it from closing.
Another little tip is to check the idle with diagnostic port jumpered (believe E1) as this should set idle to 750rpm for adjusting timing at 10deg. If this does not work then its a mechanical rather than electrical issue.