Help with high idle speed!

[blackout]

Finally got my 91 talon put back together and running the other day. I grounded out the sensor and set base timing like the manual says to do and then tried to set the idle but I can't get it low enough. It idles at like 1500 rpm when I unground the sensor used for setting base timing with the biss screw all the way in to lower the idle.

Hope this all makes sense what I'm saying. Am I doing something wrong?
Has anyone had this problem before maybe a faulty sensor or vacuum leak? Next time I work on it I'm going to do a boost leak test to eliminate that.

Thx for looking and any advice...

[Millhouse]

Check the adjustments on your throttle cable and idle switch. If the switch is screwed in too far or the cable is too tight it could keep the throttlebody from closing all the way causing your high idle.

[blackout]

Check the adjustments on your throttle cable and idle switch. If the switch is screwed in too far or the cable is too tight it could keep the throttlebody from closing all the way causing your high idle.

Yeah I checked both of those to make sure it wasn't that. The weird part was the idle was down around 1000 rpm when everything was first set then it jumped to up to the higher rpm after a little bit of idling.

[projectxmatt]

Also don't forget to mention that after base was set it bumped up to around 2500RPM idle too.

[crazyquik22023]

First do a BLT. Always the first thing to check when having some kind of airflow problem. If no leaks then, I am assuming you are running a 1g throttle body, test the ISC sensor. Here is a good youtube how to... http://www.youtube.com/watch?v=KibYz...82D1168B54F1D4 Also did you have your coolant lines hooked up to your throttle body? If not you are going to have to either get a FIAV blockoff/bypass plate or permanently close the valve in the fiav for the car. No doing this when removing the coolant lines from the TB will result in a high idle.

[jack_of_trades]

I have seen the biss o-ring get torn when it hasn't been adjusted in a long time. That can definitely cause high idle issues at times. A BLT can expose this if it's our issue.