Cold Start Idle Speed

Howdy !! I'm new to this group after having just bought a gem of a "90
Civic Si. A great little car with a few odds and ends to putter away at;
one of which is getting the proper cold start idle speed. It's an Si
model with 1.6L 16 valve engine. On any morning on cold start (minus
temps right now), the idle speed is only about 1000 RPM. This seems way
too low, especially when it's -20C in the morning. After the engine is
warmed up from driving, the engine assumes a normal idle speed of about
750-800 RPM. Funny thing is though, after only about 5 minutes of
driving when the engine isn't fully warmed up, the cold fast idle
increases to about 1500 RPM (normally as engine warms up, idle drops).
My question is how is the fast idle adjusted ? My Haynes manual shows
just setting throttle cable tension and idle speed, but nothing about
fast idle. I'm an auto technician myself, and always refer to manuals on
something new or different, but I'm out of luck with this manual. Would
any of the Honda techs lend me a hand ?? I'm kinda leaning towards the
EACV ?? Thanks !!

D.Mills
Licensed Automotive Technician.