^ The valve on the throttle body would be the FITV, fast idle thermo valve. It's purely mechanical in operation, and controlled only by coolant temp. However, even w/o that valve (if it was blocked off or not working at all) the car should be able to idle by itself when cold, just not such a great idle. There's another valve (I think this applies to your year also), the Electronic Air Control Valve, EACV which is controlled by the ECU for controlling idle.
It's possible that the high idle (although you adjusting the base idle w/ the screw makes it harder to say for sure) is caused by the FITV giving too much air when cold and maybe the fuel system isn't able to supply enough (for whatever reason) to match it - the fix being to remove it and screw it's internal plunger all the way in . Otherwise maybe the EACV isn't working until warm, although a properly running car would still idle w/o the EACV, it would just be very low (that's the base idle).
Just the first things that come to mind, as you clearly have an idle issue, regardless of the cold-start problems. They could be unrelated also. If you make sure the FITV is screwed in all the way, and get the base, fully-warm, idle set correctly (a service manual would have the exact rpm), it will then be easier to determine what the actual cold-start problem is.
Last edited by A-series; 02-14-2009 at 12:02 AM.