Nylon idle adjusting screw

[1oldpoop]

Greeting members, this is my first post to the list, as I just purchased my NSX two days ago. It is a 91' automatic, and the idle speed is about 400 rpm too fast. Looking through the service manual, it appears the idle is adjusted by a nylon screw atop the throttle body. However, the screw does not want to turn, and the edges of the screw slot seem inclined to give way if I try and force it, so I haven't done anything. Am I missing something? Am I looking at the wrong screw? Any suggestions?

Thanks,
1oldpoop

 

[Briank]

You did not say what your idle was?

Yes you are missing somthing there is no idle speed adjustment screw on an NSX. The screw you are trying to adjust is a factory setting to set up the throttle body and should never be adjusted. The idle speed is controled by the ECU and the Idle control valve on the throttle body. If your idle is to high then you have a vacuum leak or a bad fast idle control valve.

Use the search function above, there is tons of info on idle problems here.

 

[warrenw]

The '91 service manual does show an idle adjustment.

 

[Briank]

Somthing is lost in translation, yes there is an adjustment but it does not adjust the normal idle speed which is 800 rpm, as shown in the manual the adjustment here is for 600 rpm which is to set the minimum air flow at idle so the EACV and the ECU can properly control the idle speed to 800rpm. If this adjustment is unmolested the only problem you will see is low or hunting idle, and that is fixed by cleaning the throttle body.