gammey4

How is your catch can routed again? And do you want to me up on the 19th?

When is your next day off?

Happy birthday mike

I’ll give it a look later. Did you end up getting the tuning school course?

How’s it running anyway?

Why don’t you just have a shield put on and never mess with it again? Pretty sure I suggested this last year also.

Idle trims are the same concept as fuel trims but apply to airflow correction. Ecm uses both to make corrections but only stit and ltit for speed correction, spark for fast (crude) changes and iac counts for slow (fine) changes. And knowledge? I have none, I’m just a mouth breather.

Long term idle trims and short term idle trims, not fuel trims. Reset the iac , remove the tps and iac connector, turn the key on for one minute (don’t start it). Turn key off and plug both back in. Start it and see where the iac counts settle at. Honestly if it were mine I would open the throttle blade a little. Make sure the tps voltage doesn’t go above .8 volts when the throttle is closed.

The timing at 23 to 30 would suggest to me it’s an airflow issue. The ecm is adding a lot of timing trying to bring the idle up. If the iac counts hot are higher than 60-80 than it is wanting more air at idle. Can you monitor stit and ltit on your scanner? And what is your map kpa at idle? Timing at idle for a stock 6.0 will be around 12-14 degrees. 23-30 means it maxed out the adaptive spark and then it will add iac counts to try and bring the idle up. Unfortunately the adaptive iac routine is pretty slow to update so if it overshoots it you will get a lean surge. I wouldn’t get to wrapped up in the maf readings at idle. It relies on the map sensor, maf is only referenced as a sanity check. Reset all your fuel trims and iac while it’s hot and see what it does.

Iac counts should be fairly steady around 60 at idle. Have you checked the air passage to it? Also the hole in the throttle body? Maf hertz at idle should be around 1,200-1,500.

What are the iac counts when it’s surging? Timing also and fuel trims.

I just set the cruise at 73 and that’s all. I’ve got a hour drive so I don’t try and make it any longer by babying it to get any better. Your car just has a on/off switch where the accelerator used to be lol.

A lot better than I expected out of it. My Cruze did 36.5 average on the same daily trip.

Only one I have on my phone right now. It’s a 2020 lt1

That’s the same question as asking “why does your clutch slip when it gets hot?”