brake/idle issue on 93 s13

[remzon]

Hello all. wondering if anyone can help me out here... my 93 240 sx se sat around for most of the past winter spring and summer and i just started driving it again a couple weeks ago. did a bunch of general maintenance to bring it up to par, like oil change, new fuel filter, new battery and new alternator(though it turned out all i needed was the main fuse) the issue is that when i depress brake pedal when i'm idling, RPMs drop 200, then adjusts back to proper idle at +/- 750. when i come to a stop at a light or wherever, RPMs will drop down to 400 or so, then go back to normal when i let go of the brake. i checked brake booster line and i have good vacuum and i also checked the one way valve, seemed ok. ANY IDEAS??? also might not be relevant, but i can hear rushing air in the vents when the clutch is not in, and the sound of the rushing air stops as soon as i put clutch in. i thought that was weird.....anyways any theories are much appreciated. THANKS!!

[remzon]

i meant to post this in the online mechanic forum, sorry.........

[grecco28]

ok, for the idle drop you have to check if you aux air valve (aac iacv) is working properly cause when you brake rpms tends to go down, this is normal issue, mostly in automatics...

for the noise issue probably is the throw out bearing in the clutch or the pilot bushing.. thats why when you step the clutch goes away...

[remzon]

i probably should have specified mine was 5 speed manual, but i'll check my iacv valve. thanks for the tip. it's not life or death issue but i'm worried she'll stall once winter hits. it just occurred to me too that after the winter i had to top up my cluth fluid. i had no pressure and the clutch pedal was stuck to the floor. i could pull it up with my foot, but it would either remain all the way down, or all the way up. didn't look like it was leaking from anywhere though. and ever since i topped it up it's been fine... i'll have to take another look.