Ford ISC-BPA

[Mike Brown]

Dave,
	You know the duty cylce of the pulse width so you know how much air you
are passing, at least percentage wise.  The feedback path is RPM.

Mike

Dave Williams wrote:
> 
>  How does the Ford idle air valve work?
> 
>  From the initial descriptions I found, it was a solenoid, pulsed
> rapidly to shuttle the valve open and closed to meter air.  Now I've
> found some descriptions that make it sounds like it's fed a pulsewidth
> modulated signal that varies the voltage, pulling the solenoid only
> partly open as needed to meter air.
> 
>  Using it like a shuttle valve would be easier in software; using it pwm
> would be harder since you could never know exactly how much air the
> valve was passing, since there would be no feedback from the solenoid's
> position.
>