Steve,
Sounds like your idle control valave is working okay at least it is acting like it is. I have a feeling that there is something else up for you. The normal idle for these beasts is 650 rpm +/- 50 rpm
whether in park or drive. So something is amiss. I believe it is probably an electronic sensor or a vacumm problem. The fact the idle is always high and not rough tells us that something is misreading the current idle speed or not adjusting it down. I am afraid I am not much help. Do you have a good shop that can scope the electrical side and gas emmission levels. Although this is probable only going to show a sympton of the problem. It might help narrow down the search
m

__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)