Momentary high idle?

[KiltedBanshees93GT]

I was working on my car today and noticed that when the car is idling, it is at about 900rpm, but if you blip the throttle, the car idles up to about 1000-1100, holds it for about 2-3 seconds and then drops back to 900. Any suggestions as to what could be causing this? MAF need cleaning? I'm planning on doing a full tune up before we move, but I dont know that it'll help,
Any suggestions would be appreciated,

J

[RPM427]

Pick up a new TPS sensor (on top of the throttle body).

[GhettoPop]

similiar situation.....idles at 750, rev to 2k or 3k, it will drop to 1k. hold for about 2-3 seconds, then back down to 750. i thought this was normal............