I been having a problem with my IAC. The car is set to idle at 750 from Ion but it will only go down to 800, but when I put the A/C on the engine almost dies. I bought a new IAC and am about to install it. I have been reading my GM manuals and all I can find about the TB blade position is that it's set by GM "almost closed" and is calibrated to the counts of the pintle of the IAC.
I set my blades "closed" and set the TPS to the proper volts. My concern is that i may not be getting enough air at idle and part throttle with the new 355. I wonder what GM means by " almost closed" ???

 

What are your IAC counts?

 

http://members.***.net/chipsbyal/page/idle/#stocktbi

 

Thanks...That's a great write up. I'll look at my BBK when I get home today and compare.