I built the V3.0 board months ago using the pullup resistors and single VR conditioner with modded CAS. I would like to use a stepper motor IAC as well as the additional features of the MS2 card.....can I use the MS2, and what other mods or firmware will I need?

 

What are you trying to drive with the stepper controller? The BAC valve on a 2nd gen is a PWM valve...

You can use the ms2, and will need ms2/extra 1.0.2 or the latest 2.0 beta.

Ken

 

I had originally planned on using the stock BAC, but lately I decided to populate whatever I needed on the board to drive a stepper motor IAC such as that used on Chrysler products. I found this and thought it would work well, perhaps better than the thermowax and pwm bac:

http://www.diyautotune.com/catalog/c...a2feec5843d616

I mainly wanted to make sure the ms2 card would work with the single vr and modded CAS before I purchased one.

Oh by the way, did we lose a bunch of Megasquirt threads?....I was looking for the thread that addressed CAS wiring and it looks as if many older threads disappeared.

 

I don't know if we lost older threads, but it's possible.

Using the BAC with no thermowax is probably the best option. Stepper IAC motors are very slow, and people have had a lot of problems getting them to work properly.

The BAC however responds fast enough to changes in duty cycle to actually use it for closed-loop idle-speed control.

The ms2/extra code will work fine with a single VR and modded CAS.

Ken

 

So without the thermowax I can use the F-idle circuit to run the air supply valve on the UIM during cold starts? I only want a cold fast idle of around 1800 rpm or so and the supply valve is adjustable.

When I built the 3.0 board months ago I added the upgraded transistor to run the BAC, so I will stick with that plan. Thanks for the info on that.