Curious - the ambient idle (that's controlled by the IAC), what happens if it's not in diag (jumper pins) mode and you make an adjustment ? Seems mine idles close to where I want it with the adjuster all the way min (or turned almost completely shut) - I'm wondering if somone b4 me made adjustments w/o the jumper in place?

I have funky idle it can never decide exactly where it wants to sit. I set it with the pins jumpered ~1200 (to help with idle drop) and set the mechanical idle to the same but still see dips when first starting up on hot or cold starts. I don't make many changes to fuel and timing near idle - adding 5deg timing and -5% fuel (roughly) due to the big injectors (550's w/Xede). Is this just going to be part of living with 550's ? It's kinda a 2 part Q..