MSefi.com read only forum (Jan.15,2018)

I am in the process of building a MS1 V3 board and have a question about using a FORD PWM Valve as a FIdle valve.
I know the manual says that NO PWM for MS1 but If I limit the flow of bypass air with a plug/orfice and use the valve as a MS1 grounded switch where switched 12V is applied to the valve and the FIdle circuit supplys the ground pulling the valve full open when I need fast idle. Why won't this work? What am I missing?

AFAIK Ford pwm type IAC valves won't work with a steady state current. It has to be a pulse width modulated signal where the width (on time) of the pulse at a particular frequency (80 to a few 100 cycles) controls how much the valve opens. There are IAC valves that work just as you describe though.