type44? Fwd: Re: ISV

[Huw Powell]

> Again, my ignorance is playing out here. I know what the ISV is (after
> numerous cleanings...) but what is the idle switch? What's its job? Where is
> it? Who is it dating?

The idle switch is usually mounted to the throttle body, and on most of
the later cars (85 on?) shares a 3 pin connector with the wode open
throttle switch.  It "tells" the ECU that your foot is off the loud
pedal, resulting in a couple of things.  One, is that if the engine is
still revving, it sends a negative voltage (current?) spike to the
control pressure actuator to cut the fuel immediately to lessen
pollution and waste.  Another, is once the engine slows down, the ECU
"knows" to use the ISV to regulate the idle.  Also, with the idle switch
closed, the engine won't rev over about 1300-1400 rpms (mine broke in
closed mode once, *that* was fun!).

It is often mounted under the throttle body, and actuated by a metal tab
on the lower end of the butterfly "axle" rod thing.

It is dating Madonna, believe it or not, but not exclusively.

--
Huw Powell

http://www.humanspeakers.com/

http://www.humanthoughts.org/