IAC modifications

[bruce plecan]

After installing too big of cam in a GM TBI system.  I say too
big, cause numerous chip programmers said it wouldn't work.
At one point in time I had a huge problem with the idle speed
being erratic, and hunting around.  With the scanner I could
see the IAC varing.  So after much experimenting I had some
new cones machined for the end of the AIC shaft, as I recall
they are a 6-32 thread.  Had only about .015" taper for the
lenght of the cone, and then used an electric drill, and 
file to get the taper right for cold starts, and hot idle.
While the computer uses the IAC during cruise conditions, I
never experienced any problems, with cruise conditions with
the custom taper cones (pintles).  Final cold idle was 1,100
rpm, and hot idle 650-700, and electric rad. fan has only min.
effect now on idle speed.  Also, bought a stepper motor
controller kit, at an electronics store, slowed it down, and
put a GM connector on it, so I could run the pintle in+out
on the bench, rather then having to go thru the IAC routine.
Had a spare TB housing so I could set it, on the bench.