I have one or two cars that just dont seem to "stay" in open loop somehow.

First the one car had fuel trims stored but wasnt updating, then I cleared the LTrims and it started learning again (operating in closed so it should have) then after a while of driving under nothing under a load would count LTrims

It is a huge cammed car and does the normal split BLM at idle, so I am figuring out a way to at least keep it in open loop at idle

 

Just like you do on OBD1. (programming) Raise the closed loop enable temperature to maximum available.