IAC #'s

The way I did it in the past was to notch the throttle blade to allow more air thru.
 
If your car is idling fine I would just leave it as it does not affect anything outside of idle. I have a slight case of OCD so if you're the same and feel you need to hit a certain number, I feel your pain :D. But in reality there are no magic scan numbers.
 
Definitely get a TT or Bailey chip in there. It will improve driveability and idle quality among other things. If you're planning on more mods might want to look into a suitable injector and chip package as the chip will need to be reburned anyway if you decide later to go with bigger injectors.
 
I am doing some cleaning and tuning on my car. I can not get the iac numbers lower than 45? I have the TPS set at .42 and 4.58
Turn the idle adjustment screw clockwise to open the throttle blade. This will cause the idle speed to increase. The computer will then start closing the IAC to bring the idle back down to the target speed. After you get to the number you want,reset the TPS.
 
Also make sure you are checking the IAC numbers in park, warmed up, with the A/C off. As previously mentioned 45 isn't atrocious but if you are OCD you can turn the idle screw and reset the IAC & TPS until you get it perfect.
 
You will want to turn your IAC screw clockwise to the lower number. Make sure you adjust your TPS after because it will change. Also make sure your car is at 160*

IAC 10-20
TPS .44/4.5wot
 
The iac motor must be bad because the more I turn the screw clockwise,the further the numbers go up. The car still gas everything original.....so it warms up to 190-200. I made the adjustments slow and a little at a time, waiting in between to wait for the idle and numbers to settle back down.
 
The iac motor must be bad because the more I turn the screw clockwise,the further the numbers go up. The car still gas everything original.....so it warms up to 190-200. I made the adjustments slow and a little at a time, waiting in between to wait for the idle and numbers to settle back down.
You have to open the throttle to get the numbers to go down.
 
Yes, when I open it the numbers go up? So something is wrong. I am thinking the iac motor must be bad?

No, you're turning it the wrong way. If IAC goes up when you move the throttle blade, then you need to adjust it the other way and see what happens. The idle TPS volts will rise when you open up the blade. That's another easy way to see that you're moving the set screw in the right direction without even starting the car. This is why you need to adjust the tps as you open the throttle blade to lower iac counts otherwise the idle TPS volts get too high and outside the window with which the ecm knows that the car is idling.
 
I readjusted the TPS to .44 and tried again to adjust the iac lower but got the same results. The more I opened the blade the more the numbers went up. When I closed the blade I was able to get it down to 45-50
 
I readjusted the TPS to .44 and tried again to adjust the iac lower but got the same results. The more I opened the blade the more the numbers went up. When I closed the blade I was able to get it down to 45-50

No, the iac doesn't go up when you open the throttle blade. Do the idle tps volts go up when you open the blade? Adjust it and tell us again what the idle tps volts are BEFORE you adjust the tps sensor again. It's a balancing act. Turn the throttle blade until you see .48 or even .50 idle volts on the scanmaster from where you have the throttle blade set now. THEN adjust the tps so the idle and WOT volts are .40-.44 at idle and at least 4.4V at wot. THEN start the car, warm it up, and let us know what the iac does. It doesn't really matter what your current tps volts are. You need to see via the volts that throttle blade has opened, adjust the tps to correct range, and then start the car and report back on iac counts.
 
I readjusted the TPS to .44 and tried again to adjust the iac lower but got the same results. The more I opened the blade the more the numbers went up. When I closed the blade I was able to get it down to 45-50

The TPS volts will go up when you adjust and the iac will come down, but the car won't know it's idling until you get idle tps volts back at .44 or less so this is probably why you're not seeing the right results. You're opening the blade, but the car then thinks it's not idling. Another good reason to adjust it with the car off; the ecm resets the idle reading from the tps volts when you restart. If you adjust it too far, the ecm thinks you're giving it gas by opening up the blade while running.
 
The TPS volts will go up when you adjust and the iac will come down, but the car won't know it's idling until you get idle tps volts back at .44 or less so this is probably why you're not seeing the right results. You're opening the blade, but the car then thinks it's not idling. Another good reason to adjust it with the car off; the ecm resets the idle reading from the tps volts when you restart. If you adjust it too far, the ecm thinks you're giving it gas by opening up the blade while running.
I will try this procedure tonight and report back, thank you
 
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