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

Alrighty then. I finally got fed up with the stepper motor doing odd things while trying to get my truck started, so I ripped it off. A few minutes ago, I decided to really see what wires did what. Out of the 5 wires, 2 move the damn thing.

Using a battery charger for a quick power source... With positive on one wire and negative on the other, the motor contracts completely. With the leads switched around, voila, the motor extends fully.

Now, which wires from the MSII harness should I be using (once I know which ones to use, I can swap them around if the motor does the wrong thing )

IAC1-A
IAC1-B
or
IAC2-A
IAC2-B

Thanks in advance.

Welder.

The manual has all sorts of information on IAC stepper motors including wiring etc.

http://www.megamanual.com/ms2/IAC.htm

Ooops, left one thing out.

From your description it sounds like you have one set of windings open in the IAC motor.

Ken

Are you sure this is, in fact, a stepper motor? It sounds to me like you may have a DC servomotor and the other three wires are a potentiometer for an IAC position sensor. What exactly is this IAC out of?

Matt Cramer wrote:Are you sure this is, in fact, a stepper motor? It sounds to me like you may have a DC servomotor and the other three wires are a potentiometer for an IAC position sensor. What exactly is this IAC out of?

You may be onto the problem there Matt.

It is from a 91 Chevy Sprint 1L non-turbo.

Welder

Hmmm, I can't find much information on that one. The nearest equivalent I was able to find in Alldata is a '91 Geo Metro 1.0 liter, and that one looks like it uses a PWM or on/off valve.

I am going to scrap using the thing period.

I don't mind keeping my foot on the pedal while warming it up.

Thanks again.