Adjusting fast idle speed on CIS

I don't know if someone else has allready figured this out, but I'll post it anyway. You can make the Auxilliary air regulator (which controls fast idle speed) adjustable on CIS. The procedure is even easier than making the WUR adjustable, and once done adjustment is done in a similar way (by "knocking the plug"). On the tail end of the regulator you'll notice two plugs on opposite sides of the tail. One is small and bronze colored, and the one on the other side, opposite it, is aluminum. The aluminum one is actually just a cap pressed in and not the actual plug. By drilling a hole through the center of the aluminum cap you gain access to the other side's plug allowing you to knock the enclosed bimetal spring to one side or the other internally, depending on which plug you knock (right side or left). If you knock on the exposed plug (the bronze one) you will raise fast idle speed. If you knock on the one under the aluminum cap you will lower the fast idle speed. It only takes about .020 to change the speed about 500 RPM. Use the drill appropriate for a 1/4-20 thread (I think #7 drill), as you will need to tap the hole you made in the aluminum cap, and insert a set screw with some thread sealer to prevent air from leaking into the unit. I wouldn't use the set screw to knock the internal plug because I think it would require too much force than the threads on the aluminum cap could take and you would strip it. Instead, go through the tapped hole with a 3/16" flat end punch and tap the plug with a small hammer. You can monitor, or measure how deep you knock in either plug by how deep or protruded the bronze exposed plug is. Of course ensure you clean all metal chips out of the unit after drilling / tapping the hole.

Hope this helps someone,
Leon 78SC

[This message has been edited by leon (edited 08-26-2000).]

In case anyone's interested