I think it sets the idle at around 600 or so.

To make sure, connect an amp meter to one of the wires on the Idle Speed Control Valve (I separate the wires at the connector and use a clamp amp meter on one of the wires). Then you can have someone press on the accelerator slightly and see what the amperage is (mA).

Compare that with idle speed.

Note: DO NOT purchase an amp meter at an auto parts store! They still think a meter with test leads and a 10 amp maximum is plenty good! (May have been good for the model T, but not modern vehicles or measuring things around the home.)

Anyway you can get a clamp amp meter which measures AC, DC, may come with a temperature probe, and has a maximum capacity of 600 amps! All for under $80 if you shop around the internet. BE SURE it also says DC (for automotive work - AC home electrical work).

FYI - For other people reading this and going Huh??? There is an "idle" switch on the throttle valve. When your foot is off the accelerator, it tells the Idle Control Unit the engine should be at idle. Pressing slightly on the accelerator turns this switch off.