Car is a 1995 LT1, automatic, 383 with cam specs 224/230 .560/.544 112 LSA. The car's IAC's are currently around 40, blades against the throttle stop in the stock position, volts @ .67.. Initially, IAC's were around 70, so I started drilling the IAC passageway in the TB and that got me to where I am today. The problem I am having is that the car has crazy split BLM's at idle - 120'ish on bank 1 and 140'ish on bank 2, but as soon as you come off idle, everything goes to 128 (or so) as it should. Car drives great - just these splits are driving me batty. At one point, before I drilled out the TB, I was able to get them much closer at idle by opening the stop, slotting the TPS and generally fooling around with it, but I couldn't get it to idle as well as it does now. I stopped drilling because most people drilled 11/32 for their 383's and that was enough. Mine appears to want more, if I am to get the IAC's down to 25 or so (which is where I read they need to be?) but I stopped at 13/32. So drill more, or start screwing around with the throttle stop and TPS as before?
Also, the car idles at 900 warm, in gear or out, and despite having a 3k stall - it still pulls against the brakes at a light. Should I drop the idle down to 825-850 or keep it where it is?
Finally, how hard is it to adjust the idle in the tune myself? It currently calls for a 900 RPM hot idle, but I really don't want to hassle the tuner with this. He's worked his ass off tuning this car and he's got everything else just about spot-on. I have the laptop and have uploaded plenty of tunes in the past - I've just not adjusted anything myself before.
Any assistance or advice you could offer would be most appreciated.
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