not idiling well????

[trenooo]

hey guys quick question,
my mat has a 1994 Audi, and wen you start it up it goes to idle at around 900, and then jumps up for a second to around 1500, and then back down.
any ideas on this?
cheers

[db_notso]

um when cold cars idle higher then drop back to base idle (nearly every car out there)
is it just when cold?
is it as the aircon turns on for first time? (try with a/c off if equipped)
is there any hissing sounds like a vacum leak?