I've got my car running somewhat decent in closed loop mode (still a long way to go, but thats a different post). However it is all but undriveable in open loop. RPMs surge at random, it can barely hold an idle (idle saver engages quite often), and it is ESPECIALLY bad when coming to a stop. RPMs dip to near stall speeds sometimes, (when stopping) and sometime they will surge just about sending me into the car in front of me. I cannot yet do a true datalog that I can share, however I would like to know if there are some obvious things I can change in the meatime before I can post up a datalog for help reading it.

Because of this every morning on a stone cold startup I have to let my car idle outside for 15 - 20 minutes and its costing me some serious MPG, and old neighbors dont like the sound of a 350 idling in the middle of the court at 7 AM.

 

I've answered my own question somewhat simply by making open loop a bit more rich, but for some reason I would think there is more to it than just richening it up.

Also - default speed for overdrive is 40 mph. Am I safe bringing this down to 35-36 mph? My reason is most of my driving is done on 35mph roads where the flow is usually about 37-38 mph which puts me right at the top of 3rd gear and I figured if I could just get it in overdrive for most of that I can pick up some mileage. I'm 99% sure I have the stock 2.73 gears.

^^I've always thought this was done via computer. Maybe not, as I cannot find the value. Is there a way to change when it goes into OD?

 

I'm no expert as I have only had one (never again) auto-700r4
but IIRC it was not controlled by the ecm as far as shift points. But lockup was controlled by the ecm.