L86 lean until reaching a solid operating temperature

2017 Sierra L86, 8L90, BTR Stg2 cam, catless longtubes.

I had noticed my fuel trims were much further off on a cold start, but had not focused on it too much because I had not finished dialing my VVE in. Yesterday I spent a long time and lots of fuel on the highway with different gears and speeds, and many stops and writes to get things dialed in.

The next morning I start the truck and it is commanding over 20% positive fuel trims. This is with the MAF disabled, where yesterday my VVE was within 1-2% on the majority and under 5% for the rest.
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This afternoon I logged towing 4-5k pounds for a short drive from a cold start. With it running lean.
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Here is a log about 30min in on the tow, once everything was up to temperature for a while. The fuel trims are back closer to where they were with tuning yesterday.
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I will try in the morning for a log with MAF on a cold start vs good and warm. Maybe it will help narrow down the cause? Anyone have any thoughts of what I can check?

I assume your EVAP solenoid is hooked up and functional?

I've seen EVAP cycles throw STFT way out of whack temporarily.

I know exactly what you mean. So for that reason, some time ago I unhooked the EVAP connector, plugged port, and disabled all DTC's for it.

Here is the MAF only log from this morning just moving around the driveway with the trailer still on it. Adding 10-15% fuel for most all.
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Here is a piece of the MAF log from towing yesterday when pulling in to the drive and moving trailer around too. It was reading much closer and even pulling a little fuel at times.
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You'll need to retune your fueling after making these changes. Also, I don't see how that VVE can be right. It's got a lot of steep walls and unusual dips unless it's just going off of an unusual multiplier somewhere. VVE should always kind of represent airflow into the motor almost exactly like a dyno graph...

Thank you Ghuggins, those looks like some pretty nice changes and I would not have guessed where to start with them. I did see what you are saying about my VVE on the 3D model, and will keep that in mind.

So the changes you made,
-I noticed some are for the 02 sensors to maybe narrow down the swing and fine tune further for location in long tubes?
-Then Open loop changes which I had noticed my open loop and closed loop fueling % error’s were a few percent or more off from each other. Maybe helps that part?
-And then the flow rate multiplier for injector tip temperature looks like probably a big player?

On my old logs I had been logging injector tip temp and intake valve temp, but took them off a while back when reducing how many channels I was logging. I now have added those back for logging. Any others you suggest I should add while I am at it?

I also made some changes to cat warmup injection timing modifier to hopefully get a fuller burn to better go along with that injection timing table. Let me know how it does.

As far as logging goes - the newer platforms like these have some pretty good comm rates, so doesn't hurt to log as much as you can.

I seen the cat warmup change, but did not know what to think of it since I had most my cat stuff disabled.

Yesterday I had lowered the SOI by 10 points (vs stock) in the idle area to get the more efficient burn like you recommended I try some time ago. I then finished fine tuning the idle area VVE and MAF while normal operating temperature. And tried to better adjust the VVE areas in the places I can not log.

Today I pulled in the changes you posted and did a quick log while the engine was still nice and warm and then one with it cooled. Both are just a quick idle with A/C on and off and then 1000 rpm idle with A/C on and off. It does look like it may have started bringing things closer. At least in the idle area it is around 5% off now. Tomorrow I will have a log with a cold and warm drive to better compare.

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You can chase the unicorn by tweaking things another percent or two - may not even be a bad idea to get it down to 2 or 3%, but if it's within 5% I'm not sure I would worry if it's just when cold - that's if it goes back correct when at temp...

A log on the street did show me it is certainly going the right way. I am now logging a chart setup to match injector flow rate density multiplier using fuel trims and then multiplying them by -1 to invert the positive/negative values. Then multiplying by % half in the tune file.

Thanks for showing me this GHuggins. Also thanks for fixing my cat warmup table to match the SOI table, I did finally notice it was still in play.

Not a problem. Glad it worked out for you.