I tried searching, but I'm not coming up with an answer to my issue. I have a 99 TAHOE with a 5.7L vortec, 0411 PCM swap running an 02 OS, dual electric fans, Camaro segment swap(modified the request wire so it would cycle), marine intake, and a 454 throttle body. My issue is the original throttle body that came on a 5.7L is 75MM at the top, but necks down to 69MM just below the throttle blade, and the throttle blade has an airfoil on it that is almost a 1/2" tall on the blade itself. The 454 throttle body is a full 75MM straight through with no foil on the blade. My problem is GM cranks the IAC WAY open at low throttle positions to offset the foil on the blade, and with the larger throttle body I have a very touchy pedal because of all the IAC airflow. Running along at 40-45 it doesn't want to go into lockup or stay once in because I'm giving it so little throttle because of all the IAC airflow. You can watch it on the scanner crank the IAC open and it gets difficult to hold speeds below 50 because of it. I'm pretty sure it's throttle cracker and throttle follower I need to adjust(I've been comparing my values to those in a 5.7L LS and 5.3L truck), but I cannot find much info on tuning for this kind of issue, and I don't want to screw anything up. Any help is greatly appreciated.
This is what is currently loaded in it.
3GNEC18R8XG208839 segment swap for fans & tires-4.ctz