problems? or am i paranoid?

[tasty danish]

i'm not sure whether to chalk this up to paranoia of my new car (92 by the way) breaking or if this is actually a problem but here goes:

first off, i noticed today while driving home, that when i came to a stopsign and came to a full stop, with the clutch and brake pedals fully pressed, that the engine idle stayed up at about 3k and didnt drop.
i left the stop sign and it took off just fine and as soon as it was in gear the rpm's didnt act funny.
it only did this once and didnt act up at all except for when i was at the stop sign. fluke or something?

one more question:
i don't know if this has always been around but i just recently noticed a rather quiet, high pitched, kind of whistle coming from under my hood when the engine is above 3.5 or 4k.
i just recently noticed it and i can't seem to hear it all the time.
i was wondering if it was related to the silencer cone being removed?

a little background on my car is:
92 mtx with 120k on it.
just did the upper 60
original owner took really good care of it (first 60 was done)
as i implyed above, i have no silencer cone in the intake.
no CE lights, ever.
the car drives ultra smooth and has no glaring problems that i know of.

if i'm being paranoid, forgive me, i'm a newbie and really don't want anything breaking with this thing.

 

[PROPHET]

Check for vaccum leaks, especially by the little black canister close to the firewall on the intake.

Also you don't want you clutch engaged while you wait for the light to turn green.

 

[tasty danish]

but wouldnt a vaccum leak cause problems for more than a few seconds?
wouldnt it run pretty crappy?
also, how do you recommend i check for vaccum leaks?
thanks so much.

 

[PROPHET]

Engine runing, car in neutral, parking brake engaged, lift hood, the intake hoses that most likely be leaking will come from the black canister hoses from behind the intake to the secondery butterflies, i'm thinking one may have a little crack on it.

On the black canister two hoses one little twistee one that goes the intake plenum a few inches long and one that splits into two to the butterflies.

In my case the little twistee one was cracked at one tip and causing a leak, i removed it, cut a little piece off and reinstalled it and solved my problem.

And this problem would be most noticeable at idle, especially coming to a stop.