adjust idle speed and mixture (1 Viewer)

[HenryG]

I am adjusting the idle speed and mixture screws in accordance with the lean drop method. The idle speed screw has no more adjustment to lower rpm. It is sitting at about 900. I can still adjust the idle mixture screw to increase rpm but with no more adjustment to lower rmp to 690. What is going wrong?

i have a fj62 3f carb (Oz version)

 

[FJACS]

You possibly have a vacuum leak. Check hoses, connections and around the base of the carb.

 

[FJ40Jim]

Either the choke idle speed screw or the AC idle screw is holding open the throttle.

 

[DrRock]

Either the choke idle speed screw or the AC idle screw is holding open the throttle.

This. I just did this on my truck and was struggling with the same problem you are having. While I was in there, I also lubricated all of the linkage joints. Good luck!

 

[FJ40Jim]

Here's a helpful pic of 3F carb.
Green circle = idle speed screw.
Blue circle = AC/emissions idle up screw.
Red circle = Choke speed screw.

Make sure the blue & red screws are not holding up the idle speed.