IAC

[bruce plecan]

ref  cloud
  ref this IAC/solenoid idle control:
What are you trying to do, if you just want a min idle speed adj.
I don't think you might have to worry about any enrichment.  It's
only the smallest amount of air being bypassed.
  If you have a leanness, why not just trip an in-line resistor
to lie to the ECM about the engine temp, and richen things that
way.  
  Looked but couldn't find it, there was an article in Popular
Hot Rodding (I think), that used a Howell modified Holley TB.
The modification was on the backside they added a GM IAC.  May
have been a 4 barrel, but calling them or if someone could find 
that article might be an answer.
  Why not try just going to a recycling center. If they have a
cores area try that.  Make sure the butterflies pretty much match
what you have. 1.8"'s 350 Truck, or 2.0"'s BBC Pick-up.   
  You could then have a stepped motor controller retract the pintle
like when A/C on, or when ever the problem occurs.  
  Bruce   nacelp at bright.net