idle adjustment, anyone know how? Options

[batcavee00]

does anyone know how to adjust the idle on the 2.2 celica? my idle sits right above 1k rmp and i want to drop it a little without retarding my timing. i was looking to see if there was some kind of adjusting screw like most cars, but i didnt see anything. can anyone help me out? thanks!

[Special_Edy]

Pulled the 5s throttle body and cleaned the heck out of it. Then installed new plugs.

Now idle is way up to 1200. Went back took apart the IAC and cleaned it up, and set it for lowest. Now sits at about 900-1000 RPM, not the 750 in the manual, but makes the touchy idle a little calmer. Not intended either, but works.

Double check the ignition timing, it will raise or lower the idle speed if it is not at 10° BTDC. Also check vacuum lines as a vacuum leak will raise the idle. With the engine warm not hot carefully spray starter fluid or carb cleaner around the vacuum lines and the intake, if your rpms increase more you have found the leak.

Does the idle remain the same or drop when you turn on the AC compressor? If it drops to normal rpm with the compressor on then you may likely have a bad AC idle up control valve(not to be confused with the Idle air contr valve) I had one of these go out on me.
The second idle up control valve is located behind the engine on the Power Steering Rack on the passenger side of the car. The hoses connected to this valve are prone to coming loose and falling off.

Also check that the accelerator cable has a tiny bit of slack and isnt holding the throttle open.

Once you have made sure that none of the above items is the cause you can lower the idle speed by adjusting the throttle stop screw. On the throttle body where the accelerator cable connects you will see a small diaphram that pushes the throttle open. Just inside(1/2" closer to the throttlebody) of where the tip of this acuator pushes the throttle is a second screw(mine happens to be a threaded rod with a nut). Loosen the nut and turn the threaded rod farther in till the idle drops to the correct speed. Tighten the nut and you are done.

Try this stuff out and let us know how it goes. Good luck

The idle adjustment screw is a stud and nut on my 94 GT with a 5sfe