Ok its been getting worse lately that when I turn the defroster on or even the A/C/Heat the car wants to drop RPM's real low and at times it even Stalls on me. I have tried adjusting the BISS Screw but its only now makesthe overall car idle real high which I dont want. I am at 860-980 RPM's on average normal Idle once the car is warm. Im on Speed Density running Tephra V7. The car only does this when you come to a stop and sit not driveing. The IAC motor was replaced recently to trouble shot other issues that tuned out to be something totaly Differant but its new less then 2k miles on it so I know its not bad. The majority of my Mods are in my Sig to assist. Any help is greatly appriciated.

 

How old is your battery? also, check out your positive battery terminal, I just had to replace mine after it caused much headache.

 

Battery is still good its putting 14-15 volts constant on the digital volt reader. The terminals are new so they are good.

 

might be a shot in the dark but check all your negative wiring, for your grounds....if your gettin a bad ground might cause erratic issues, i dont recall where all of the ground points are underhood, ones by intake mani to strut bar,and ones on passenger side by intake mani iirc....look up a diagram on here search, then check that as the next thing...good luck

 

Did you sent the BISS per the manual?

 

If the iac was bad id throw a code also the iac was just replaced.