I've starting using this feature and it seems to work pretty good.

Below post is from Rob @Adaptronic.

From our experience so far, when using ignition timing for the P and D idle control components, the P and D gains need to be alot higher (about 10x higher) than typical values using an idle control valve only. That also means that yes the P and D gains are still used, they simply affect the ignition timing for idle control, rather than the effort for the idle control valve.
When using ignition timing for the P and D components, remember that the integral component of the PID controller, and the base effort, and all the extra efforts, only affect the idle control valve!
If you are getting idle hunting with small P and D gains with ignition timing idle control, the P and D components are probably doing hardly anything ...

 

Yes, the P&D timing is how the big dogs like MOTEC, and OEM do it. This is definitely the way to go.

 

I do admit, when I first read about this update I thought it was just another feature for me to foul up. Especially since the P and D need to be higher. Seems like there is more room for error. My idle is decent right now but maybe I will give this a try.

 

I'm still on the V3 and I have everything working fine. Is it worth messing things up to try this out?

 

My idle was fine with oem injectors. When I put the 460's in I had trouble the ac compressor stalling out the car. The ignition timing idle seems to have fixed this issue.

 

Can you post your new map?

 

work in progress ...

 

I found a direct relationship between the spark advance and idle speed when tuning my MS. Making sure to lock the timing at a constant is what really helped me; 12* without a/c and 18* under loads...so I could see this working inversely if the idle valve doesn't move.

 

Thanks!

 

It's a bit weird, because the I value gets applied to the IACV, and the P and D values get applied to the ignition timing.

After I rebuilt my engine with big cams it was hard to get it to idle consistently. The IACV didn't have enough range, so I'd have to set the idle screw to give me enough air to idle when cold, but then there was still too much air when hot. This meant I had to do a lot of manual tuning using the ignition map just to get it idling acceptably.

Switching to using ignition for idle control sorted all those issues out instantly. Because the response time of the engine to ignition changes is much shorter, it also seems to eliminate the tendency to get oscillations in the idle. Now it's very steady around the set point, regardless of temperature.

In short, if you're at all unhappy with your idle, I highly recommend enabling this feature.