Anyone set this up on a miata yet? Especially anyone with a 99+ idle valve on the ms3x output I've been using the timing adjuster thing which rocks, just haven't had time to mess with the IV table.

 

I tried it. it works pretty well as long as you don't use the NB alternator control.

the reason is this: NB alternator control doesn't change the system voltage when there's more idle load, but rather it increases MAP because the alternator just pumps up the juice to maintain steady voltage...

but the initial duty table doesn't account for MAP so... it sets the wrong initial duty.

 

do you have the settings you were using?

 

In for settings since I'm using the le sexy NB throttle body.
With MS3X do you need any "PWM frequency multipler" box for the NB idle valve?

 

I don't have the initial values I was using. But I tuned it in a parking lot in 5 minutes. Get the car warm, note the idle duty, put it in that spot for that MAT value. Maybe add a little bit to be safe. You can check logs for other MAT values or make some best guesses.

I run my NB idle valve at 383 Hz. Works great.

 

no need for a multiplier box with the ms3X, I do suggest installing a flyback diode over de idle valve to bring the duty back from 70ish to a more normal 30ish %.

 

Uh, you need to spoon feed me this.

I read this - https://www.miataturbo.net/megasquirt-18/ms2-vs-ms3x-idle-duty-61914/
And then this - http://miataturbo.wikidot.com/ms2-m (part about the idle mod)

And as I understand all you need to do is take a diode from S12 to pin#3 of Q4. With banded end going to S12. Basically the "pwm idle mod" minus the whole TIP120.

 

I made a basemap with one, completely arbitrally.

Best thing would probably be to figure out where the PWM lands to idle at the RPM you want. and plug in that for your entire map. Then just increase it a bit as the CLT drops and decrease as the RPM increase.

It wont be until March sometime when I actually get the car out of storage and load the new firmware on it.

 

Its been quite a while since I owned a car with a working IAC.

 

Agreed. This is true for most solenoids that move smoothly, such as VVT.

The exception would be solenoids that need to open and close very rapidly such as boost control.

 

That would be the case if you use the idle output on the MS3 board. Instead, you are using the idle output on the MS3X board.
So take a 1N4001, connect the banded end to 12V and connect the other end to the idle output of the MS3X (pin 9).

 

Sounds easy. Is there a 12V source on MS3X or do you just go to the main board?

 

there is no 12V source you should use on the MS3X.

BUT

Your idle valve should already have 12V going to it in the factory harness.