GM IAC

[Bruce Plecan]

>What's the minimum requirements for this
>cone-shaped-hat club again?

If you repeat something silly 4-5 times before ya remember it, damage
something, or if you let the smoke out of three devices all at once that is
an
instant winner.
>
>Anyhow, my question is that the manuals I have (Haynes and the bigger
>Chilton's model specific guide) mention an O-ring for the IAC.  I didn't
>find any O-ring or gasket of any sort.  It was just plastic on aluminum.
>Should this be the case?

Some use gaskets, If there is one I use it, if not I don't go outta my way
to replace
it.
  The IAC is a stepper motor, and the ecm counts pulses sent to it for
up/down idle.  So if it get gummy and slows down in reaction to these pulses
the amount of air bypassed is wrong.
Bruce

  I don't have the full story on how the IAC
>functions but maybe this could explain the degradation at idle when the
>engine is hot with the different material expansion rates.  Dunno...just
>thinking out loud so sorry if that sounds really dumb.
>Thanks!
>Terrill