gm idle air control

[355vette]

MSII, v3--2.89 on 454 BBc with tunnel ram and dual gm tbi.

When I first started to power up I could hear the IAC's moving and that stopped before I got the motor running. I fooled with it quite a bit and finally stopped trying to use it and just got the motor running. As the motor is on a run stand I just pulled a vacuum cap at start up and replaced when warmed up. I have the motor running well enough that it is now time to install on my truck and tune further. Before I do that I would like to get the IAC working. I am looking for some test procedures I can use to troubleshoot this.
My setup in TS is:
IAC always on
time step size 2.5
accel step size 0.0
min step 8
start value 200
crank position 10
crank run taper 5
hysteresis 5.0
steps on temp page
-40 = 10
straight line to
175 = 208

When I hook up the IAC motor there is no movement
I can change the start steps in TS and it shows on the screen and appears to send to the MS

What am I missing here.

Thanks

[Matt Cramer]

Could you post your whole MSQ? This will let me check if you've accidentally enabled settings that are not compatible with the stepper IAC.

[355vette]

Here is two msq's. The 2011 is what I have been working with the last couple of days and the 2010 is the last one when the motor was actually ran. not sure if I even know how to attach msq so here goes.

2011-09-26_20.58.29.msq

2011-09-26_20.58.29.msq

[Matt Cramer]

I don't see any setting conflicts. Does loading the 2010 MSQ have any effect?

[355vette]

I could try it again but when I last used it the IAC did not work. I am using a relay board and have gone over where they are attached several times. I have swapped them side to side. I have checked continuity of the wiring with an ohm meter. I have 4 different IAC motors and one of them is new and never used before. I have two IAC plugs spliced into the system but have only been testing with one at a time. My ecu is a diy 230-c. I did one repair on a diode if I remember and I have enabled ignition control via vr. The IAC wasn't working before those mods.

[Matt Cramer]

If you turn off the IAC output and set IAC1 and IAC2 as spare outputs, can you get them to send a 12 volt signal to relay board pins S1 and S3 respectively when the outputs are activated?

[355vette]

OK, will do that. I have taken a quick look at the pages and will read up and hopefully get it to indicate. Will post back results.

[355vette]

Matt--thanks for your help. I think I have it working now. I hate to say it but I think it was a bi-focal wiring error. When I went to make a small harness to do the port testing you indicated that I saw what I had done.