Question on fuel trims?
 

For the more knowledgeable in the bunch, I have a question on trims.

I totally understand the differences between STFT and LTFT - for the most part
Just noticed something a bit curious about mine and wanted to get educated a bit better.
I have been getting to the bottom of various vacuum and false air leaks on my car and I think I am nearly there. Have to have a relook at the P-side cam-cover gasket as it has a small amount of leaking but for the most part, I leave the smoker on the car for quite some time and see little but around a small area of that cam cover.
My question has to do with how my trims are displayed on my live data.

Generally, what I am seeing is LTFT's that are constant in the + range of about 5-6% getting up to 10% when I first put the peddle to it and then settling back down again. The STFT's however seem to be reading more negative fuel than positive on average. If I let the car sit at idle, the LTFT's sit positive and the STFT's are almost always showing negative values. So I am curious as to why the LTFT's don't begin to come down too?

I would suspect that with the constant negative trims in the STFT area, the LT's would say "ok, I guess I can start trimming these numbers back" after a while where I would see the two start to even out some but that never happens.
What part of this equation am I missing then?

Cheers

Short answer is that you need to stay at a fixed rpm and load for, I believe, 2 full minutes to see the update of the long term trim with the average of the short term trim. I have seen it on my own car at a long light at idle after replacing the air flow meter. Keep in mind that if the fans kick in, or you switch from "D" to "N", the load changes and shows you another trim location in the matrix. Purge valve could open, too, and change the dynamic by making it temporarily rich, and I am unsure what the computer does with the trim updates in the scenario.