The idle speed screw is on the left side of the throttle body.
Like Mark said, on a stock car with a short neck intercooler and huge blow off recircularion housing or diverter valve it's hard to see and get at, especially if you don't know what to look for.

It's a flat blade screw about 1/2" in diameter, and it meters the amount of air that bypasses around the closed throttle butterfly to control idle speed.

It is the screw with a spring under it in the middle of this cropped down pic of the throttle body. This pic is with the intercooler and blow off housing removed so it will be hard to see this on your car.
The hole in the top of the TB throat is the idle speed air inlet hole where it bypasses the closed throttle butterfly.

I'm 30 minutes north in West Palm.
I have a few buddies up here with 930's too.

 

hey, thanks for the pic. even with the intercooler off it's hard to see, i pulled mine off to unplug the vacuum hose from the Decel valve hoping that was my high idle issue..... after a quick spin around the block it's still idling at 1200rpm. Also even though it has a fresh o2 sensor it ran much better with the o2 disconnected so i think i'll remove it as well. So unless that decel valve is "stuck" open unplugging the vacuum hose did nothing. Maybe tomorrow i'll pull the intercooler and air box off again and totally remove the decel valve and related hardware and see if i can get good access to the idle screw (maybe tape a long screwdriver to the screw) and then put the engine back together and try adjusting it while idling. Any idea how many turns out from "closed" it should be? maybe a stock spec?

Do you guys ever venture out to PBIR? Wed or Friday night?

 

i jusr realized you said " short neck intercooler and huge blow off recircularion housing or diverter valve " . Are you referring to the large cast "block" that is around the decel valve and covering the throttlebody? Can it be removed if i modify the intercooler to take up the gap?

 

well, while the car was getting new brake pads yesterday we decided to see why the idle was high. Sure enough the idle screw needed adjusting as well as the idle fuel trim. Now she purs at 950rpm. We also had the intercooler off and decided to remove the massive factory bypass valve. To say the car runs smoother and spools up faster is the biggest understatement of this millenium. It used to do this slight surging while getting into boost, now it revs so smooth from 1000rpm right up into boost and straight to redline. In fact my earlier thoughts of EFI are slowly fading away. for now anyway

 

What did you replace it with a long neck intercooler?

 

no, still has the stock IC, we just used a portion on the cast bypass valve. We cut the end off of the bypass that sandwiched between the TB and IC and used it as a spacer. Then used a piece of aluminum tubing that steps from 3" to 3.50" to connect the rubber elbow off the fuel hat to the hose going down to the turbo inlet. Very clean install. pics to follow

 

ok, here are some pics.

We sand blasted the cast aluminum so it looks silver

 

Interesting! I suppose you could have cut off the stock reducer from the BOV and used the intercooler mount/support boss, but it wold have been more work. Or maybe not if there is a hole in there from the BOV?

 

yeah, we would have needed to weld shut the side and figured the tubing would be cleaner and lighter