2k rpm at start up

Hello everyone,
My friends 89 has a 2000 rpm idle at start up. The car runs fine, no rough idle or misfiring, 20" of vacuum. When you start the car cold, the rpms shoot up to 2000, maintains for about 15 seconds then gradually falls to the specified level. I'm not getting the distinct dead goose sound from the IAC, but maybe it is on its way south. Any ideas? Thanks for your help,
JJ

It's most likely the IAC. You could try cleaning it. Safe way is to remove it and use a very soft paint brush to get the crud off the plastic bellows. More risky but effective way is to use some electrical spray cleaner (NOT carb or intake cleaner) and spray it into the bypass opening while idling. Never use the plastic spray tube though, just incase it breaks free and goes thru the throttle opening. I've done it a couple of times with ok results.