The V6 IAC for the 3VFZE is totally different to the 4 cyl version.  If
you look towards the TB, it is that 2" cylindrical thing hanging off
the right side behind the TBS.  To remove it, you need to disconnect
the wiring harness and pull some vac. lines and 1 or 2 coolant lines
from it and two bolts.  If you want to pull it, be sure to get a
replacement gasket for it first.  You may be able to clean it ok if you
just remove the air intake hose and open the throttle plate with one
hand and spray into the IAC opening on the right with the engine
running.  (IAC must be open).

Your problem however may be related to a few cracks in the 4 " dia
rubber air intake hose.  These tend to get brittle on these earlier V6
camrys at high mileage and develop holes in the crevices which throws
off the whole air-fuel mixture, especially in open loop operation when
cold starting.  They can be hard to see unless you take it right off or
pull and stretch it a lot while it is still attached.

dave mc