Idle/coasting behavior
 

My car idles about 900-950rpm fully warm accessories off, I can make it come down to about 700rpm (more normal) turning the rear defrost on, coolant temp should be fine because the fans cycle, no known vacuum leaks (but i don't REALLY know how i'd ever find it just by spraying carb cleaner?)

I haven't messed with the idle screws and drivability is fine, although when i'm coasting clutch in until i come to a full stop it leaves the rpms around 1200-1300, then cycles down when the car has stopped again to ~900-950, is it just simply a idle adjustment issue? I played with the one facing down on the back of the throttle body just above the oil filter like a 1/4 turn each way, nothing changed so i stopped there (didn't have ten/gnd jumpered)

doesn't buck/stutter under acceleration, starts easy, checked to make sure throttle/cruise cables weren't holding the throttle plates open at all... anyone that's had this minute of a idle rpm issue please give me your suggestions

...

What all is done to the car so far?

The coasting issue with the rpms could be the dashpot.

apexi intakes, blitz bov, downpipe, greddy sp exhaust

has silicone lines and what looks to be aftermarket check valves

I would start with:

1. Cleaning out the ISC

Next

2. Check the dashpot

Those are two easy things to get started with first.

UIM has to come off to clean ISC?

"Dashpot" is the one up front that holds the butterfly right?

dashpot up front is just for return to idle when dropping off throttle?

For most cars, yes. However if you don't have the AWS on the car, you can probably remove it without taking the UIM off.

What its for has been theorized by several people (from keeping the car from stalling with the plates close, to helping reduce backfiring). However when its in effect is when the throttle plates close (i.e. dropping off the gas). Those are two components which are in effect at that time.

I have AWS so this'll be a spring project then (still cold here), the proper procedure would be backing the dashpot off all the way, adjusting idle with the tbody screw facing downward towards oil filter with ten/gnd jumpered & warm to 750rpm, then do what with the dashpot?

also since it still pulls 18-19" @ 650-750rpm can i rule out vac leaks or no?

Here you go:

I wouldn't worry about a leak if you are around 18 inHg at about 750 rpms.

sounds fun, thanks