So the car starts, all is well there. If you take off within say, 5 minutes of starting it, there is no power. In park or neutral when you rev the engine RPMs will go full circle perfectly fine. Engage the transmission (Reverse, Drive, 1, 2) the car almost stalls (sometimes does).

Basically when its cold you slowly, and I mean SLOWLY climb rpms and gears up to 4th (od), By that I mean the rpms literally will not rise quickly with any amount of pedal until you shift through each gear then back down.

I dropped the pan and changed the filter at 110k miles even. The filter was 100% clogged. Fluid gushed down unexpectedly upon removing the last screw. Oddly enough, all the fluid is and was rosy red. Perfect looking fluid.

Once it's all warmed up the car feels perfect in every way.

I believe this has its original transmission (AW71). Car is now at 111k miles. Does this sound like a full flush might take care of the issue?

The weather here is getting colder, hence the problem is more prevalent. My thought is that there is dark sludgy fluid hiding somewhere inside that doesn't want to come back to the pan and gums things up until the car is fully warm.

I'd appreciate any more opinions more professional than mine.

Thank you.