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

Planning out the wiring to run a GM TBI unit with Microsquirt. The TBI unit uses a 4 wire pintle iac valve and naturally the Microsquirt just features a single wire for a fast idle valve. Would it work to use the fi output to trigger a relay in which it would apply power to one iac coil to open it and when switched off switches power to the other coil making the iac valve act as an on/off deal?

jon,

That won't work. Stepper motors depend on the coils be energized in a specific pattern to move one way or the other. See: http://en.wikipedia.org/wiki/Stepper_motor

Someone may have made a PWM to stepper driver circuit/PCB, though I can't recall off the top of my head.

Lance.