Dr. John + other Nico experts, plz help! I changed the factory adjusted idle setting!

[QuinGarcia]

In my hunt to lower my idle on my 90 240sx, I made a foolish mistake. My car was idling at 825rpm and I wanted to lower it. I tried to lower the idle speed by turning the adjustment screw on the throttle body! I have since learned that this is factory set and is not to be tampered with! And I have since learned that the screw down by the AAC is the correct screw for idle adjustment. But now I dont know how to get the screw on the throttle body back to its proper position. There are no marks or paint on the screw to indicate where it should be, and I have a feeling that if this screw is maladjusted it will throw other things off? My car still idles at 825, but the idle tends to jump around a bit more during the course of driving around town(more than it did before). I dont know if that is related to me altering the screw adjustment. How do I put it back to the factory setting?

[drjohn]

The only way I do it is to remove the air tube to see the throttle plate. Then I adjust the screw until the throttle plate just starts to open and then back it off till the plate just goes closed. This is best done with the throttle chamber off and a light behind it to get a good adjustment. This has worked quit well in the past. You will have to recheck the tps adjustment again.

[QuinGarcia]

Before you responded to my question I tried disconnecting the AAC harness connector, fired the engine, and adjusted the throttle blade screw so the engine ran at about 750rpm without any assist from the AAC. Then I reconnected the the AAC connector, fired the engine again, and adjusted the AAC screw until the idle was around 800rpm. What makes me unsure about the method I tried is that I dont know what percentage of the air at idle that Nissan intends to go through the AAC. Do they want all the idle air to pass through only the throttle body and the AAC to only contribute air under needed circumstances(like high electrical demand, etc.)? Or do they intend for the throttle body and the AAC to contribute similar amounts of air at idle? This is assuming the engine is warmed up and no electrical accessories are being used.So, for the method you use i should back the adjustment screw off until the blade closes and I can barely even see any light though it? I should only be able to fit a feeler gauge of a couple thousands through the gap if I've done it properly, correct? thanx again DrJohn