Aux Out Idle Setting
 

Well, after a three week hiatus, I went back to working on the car today. I figured, what the heck, download the latest map from Travis and give it a go.

Idle speed was super high, like 3500-4000. Even when fully warmed up it was still 2000. So, I dropped the idle air and got it closer to normal.

There was this really wierd droning coming from the air filter. I had never heard it before and it was really loud.

Loaded my previous (last) map and it went away. So, I opened my ECU file along with Travis' file side by side to do some comparisons.

First thing was Aux Out for Idle. There was come commentary a while back on dropping from 1 kHz to 500Hz, which I had done in the past. Travis' file had Idle at 25Hz.

So, I started it up on his file, got the droning, and started bumping it up. Better at 50 but still pretty loud, stable idle, better at 100, still audible but steady idle, no droning at 200 but idle got unsteady. Put it at 250 Hz and it was quiet, but unsteady.

So, what are the NB guys running for that setting?

Sounds like the exact same problem I'm talking about in my thread...does it sort of sound like a compressor?

500 or 1000hz keeps mine quiet

https://www.miataturbo.net/forum/t33907/#post394780

Yeah, that's the thread that made me try 500. So, on one hand, closer to 200 the better, on the other, the higher the better. It doesn't really matter?

It didn't SEEM to matter once I crossed above 200.

I wonder why Travis' base map is at 25Hz? It did idle flatter the lower I went, just the bad moaning noise from the intake. It was really loud and annoying.

I posted on your thread today.

Switch to 500 hz and try to change the minimum duty cycle in real time. The first time I set 500 hz the car don't want to idle, but moving up and down the minimum dc value the idle valve starts to work.

I'll change the idle speed PWM around. I don't know how it got to that frequency. The idle values are really from person to person because of the idle screw. My 70 percent duty cycle isn't your 70 percent duty cycle.

I guess I need to do another round of updates! Thanks for trying it Stein.