Weird cold & hot Idle Problem

[SpdElemts]

hey guys, i have this weird idle problem with my ca. In the mornings or when the motor is cold when i start the car it idles like it should when cold at around 1500rpms, then drops suddenly to 750 in about 30 seconds after start up (shouldnt it be longer then 30 seconds?). Which is around normal idle speeds when warm correct? But then when i start driving the car it just idles at 1000rpm. What is causing this? Any input will be greatly appreciated.

Thanks, Jeff

[RS12Turbo]

Mine fast idles for about 5 mins before it starts coming down. Could be your air bypass valve starting to crap out.