LSX454 swapped 95 BASS burb.

[shady]

Oh... Forgot.

 

[folkenheath]

First brake assisted burnout worked amazing.
Didn't even hesitate.
Stop, hold button, smashed it, spun like hell.

So it likes the new converter/trans?

I'm going to look at that decay time.
I know I changed the decay time somewhere along the line trying to get it to idle down sooner after start up.
My have changed the wrong decay time.

What's weird is when I'm off throttle, rolling, it's all good.
When I get to the last part, right at giving it a tad more brake to actually stop. The engine will real quick like dip to like 400rpm, 10-11 AFR, and
Then it'll either catch its self, or it won't.

I can let off the throttle completely and roll for half a block lightly on the brake. Idles the whole time, fine.
The last 5' when I'm in the brake a touch more, it does it.
Almost every time.

Do you have that gray brake wire hooked up to the brake switch? Not saying thats it just curious. Although if you are already pressing the brake and just pressing it harder does it, then that's likely not related. Sounds load related.

It might be something as simple as adding 50 RPM to the target idle and reteaching the IAC again.

I would chime in with my $.02 but instead you should listen to @folkenheath .
When I had my truck dyno tuned they would tune at every 100RPM increment through the whole throttle range.
Are you drive by wire or throttle cable? There is an important step you have to do with a DBW setup that will make the IAC not work properly if you skip it.
This is mine, you can see the throttle pedal map starts at 11%, not 0%. That's just a little too "closed" to idle at my target RPM with the engine fully warmed up. The IAC can only open it a certain percent past the lowest point of your throttle pedal map. If you don't change that your throttle blade will barely be open on decel.

A DBW does not use an IAC valve. They delete the IAC and just open the throttle open slightly and control it with the electronic throttle.

 

[r3dd0g]

A DBW does not use an IAC valve. They delete the IAC and just open the throttle open slightly and control it with the electronic throttle.

Correct, that is what I was trying to say. If you don't set the pedal curve to start at just below the throttle position it idles at, it won't have enough range to control idle when it's cold. I had this problem when I first converted to DBW and had to figure it out. When it was cold it would idle at 650 even though I had it set to 850 because the IAC function of the throttle body was already at 100%.