Stepper Motor/Idle Air Control Valve MS2 Wiring?

[VolvoPunch]

I have having a hard time figuring out the properer wiring needed to use my LH2.4 idle air control valve with my MS2 v3.57 box.

The MS2 wiring diagram shows that the Stepper Motor/IAC valve uses 4 wires.
http://www.megamanual.com/ms2/v3ext_wiring.gif

I am confused and frustrated so if someone could point me in the right direction that would be great. ;-)

[DAVO240]

Comes out of Pin 30 on the DB37 connector. if your using a relay board you need to jump the IAC relay. You also need to modify to use a bigger transitor for power handling....

its all on the MS website, Search for PWM Idle

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

Or you could use a GM 4 wire one...

[VolvoPunch]

I am using MegaSquirt-II EMS System - SMD PCB3.57
http://www.diyautotune.com/images/products/ms2357-c/ms2357-c_open.jpg

so changing out the transistor is not necessary or possible correct? In that case how will I run the pins from the DB37 connector do I connect to the fast idle/air intake control valve? Which pins do I use since the Volvo IAC only has two connectors.

Addition:
I am reading here LINK (http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_volvo_240_740_940.htm) that...
IAC Valves
It appears that earlier models may have used a thermal auxiliary air valve for idle control. Later ones used a pulse width modulated idle air control valve. V3.57 boards need no modifications to control the PWM valve, while V2.2 and V3.0 boards will need a TIP120 transistor, like the one included in our MK-PWMIAC mod kit.

So since I am running v3.57 I won't have to make any modifications but what is the correct wiring diagram. What pin wires will I connect to the IAC unit.

[VolvoPunch]

Help a brother out. :help:

[B-lennium]

http://www.megamanual.com/ms2/IAC.htm#stepper you can see its pin 25 27 29 31 (between the brackets)

[VolvoPunch]

http://www.megamanual.com/ms2/IAC.htm#stepper you can see its pin 25 27 29 31 (between the brackets)

I am not sure if I am being clear enough. I want to use the Fast Idle Valve (Two connectors) that was originally used by lh2.4 on my Volvo. It's an on off switch that allows extra air to get into the engine during start up. It has a power lead and a ground. Which pin from my DB37 connector will I use?

Comes out of Pin 30 on the DB37 connector. if your using a relay board you need to jump the IAC relay. You also need to modify to use a bigger transitor for power handling....

its all on the MS website, Search for PWM Idle

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

Or you could use a GM 4 wire one...

You are saying since my MS board does not need an upgraded transistor I can connect pin 30 to my Volvo fast idle valve, ground the other connector and then select the correct settings in ms.

To configure the software for the PWM FIdle valves:

* Select the 'PWM Warmup' option for the algorithm under 'Idle Control' in MegaTune.
* Note that the 'Start Value' and 'Time Based Afterstart' parameters in the same dialog do not apply to PWM use (the PWM% is dependent only on the coolant temperature),
* Select the PWM% you would like to apply to the valve at each coolant temperature in the 'Idle PWM Dutycycle' under 'Tables' in MegaTune. 0% means no current, 100% means the full 12 Volts is applied. Apparently some valves are fully closed at 100% PWM, others are fully closed at 0% PWM, you will have to experiment to see which way yours operates.

[DAVO240]

Correct, Pin 30 mate.

Its also included in the diagram that you posted up first time (FIdle)

I think MS actually grounds the valve, so power to one side of the valve and then the other side to pin 30. at least that is how mine is set up.. but my board is a version 3 and i'm running a relay board.

Assuming that your running MS2\extra setting will be.
Startup/idle > Idle Control > Algorithm> PWM closed-Loop
Startup/idle > PWM idel settings > valve mode > normal 0% = off and valve frequency 8 (works for me)

Then you'll need to play with some settings until you get the car to idle nice. Mine are as follows, this work for how i've got my car set up! I'll give the best explination of what they do as I can.

Open duty 70% - Maximum Open percentage, the valve will open no further than this value
Closed Duty 42% - The value when the valve is actually closed, will never go below this value when the car is running. and Closed loop operation has begun.
RMP adder 150 - Value that target RPMs must be near for CL to begin
TPS 2.0 - how closed the the Throttle must be befor CL begins.
Dashpot adder 5% - percentage extra the CL adds when restarting (say on the last open you had 50% open, when close loop idle starts again the first value the valve will go to now will be 52.5% so you approach the target rpms from above)