revs when idle

[chrisJDM]

just been out 4 a drive round in my fd cause its been sat in the garage for a few weeks and its a very nice evening, car loves the cool air.  Anyways, usually when the car is stopped with it out of gear and me not touching anything it revs at just below 1000 revs, but when hot it seems to rev slightly higher just about 1000, but on the odd occasion it gently revs itself when im not even touching anything, what causes this?? is it a problem?? anyone else experience the same?? is it something to do with the ecu??

many thanks 2 any replys in advance

[peterch]

is your\'e a/c turned on?

[chrisJDM]

nope i dont eva really turn it on