my S5 13BT swapped Vert i recently acquired is running into Idle prob.

from the get go, car had idle issues when engine's cold where it'd stall until warmed up, or if rev is lightly put down, it would idle very low 3-400ish.

guesstimating stock water temp, with temp more than 70 Celsius,
idle used to hold 700-725 ish without too much fluctuation.



And Now, it would like to stall even when it's warmed up, not to mention when water is cold.
it'd barely hold when water's hot, but fluctates much more.

The car doesn't have idle adjustment screw on it's BAC.
car doesn't have AWS, it is removed. it does have an airpump and passes smog.

with TMIC off, there's no hose to nipple where it's supposed to have AWS hose.
and there's another empty nipple by the oil filter.



Car has good compression and is fine boosting and pulling. but sorta bucks in accel off situation when rev's in 2-3k range.

anyone with some idea where to start?