I'm getting a slight hesitation on acceleration and a delay in shifting from 1 to 2. Not like slipping, but just a delay. No increase in RPM's. Almost like the throttle cuts back.

Mostly notice this when driving slow in subdivision or parking lot. All other shifts seem fine.

New MAF sensor installed, did not help. Sometimes seems worse than others. Strange . . . .

What RPM should 1-2 shift be?

 

My car shifts into 2nd at around 3000 rpms in normal driving...but it can be as high as 6000-something

 

clean throttle body?

 

throttle body was cleaned when I replaced the MAF sensor.
Is there any adjustments to the transmission that can be done DIY?

 

It seems that it is the feature of gs300. I have tightened accelerator cable and removed efi fuse for few minutes. It helped. But "feature" appear again .