Thanks for the suggestion.. So I did that and no difference so I put my double A F3 on and it also will not run in that area smooth it runs but if you slowly throttle her up and going it will slowly stall but on the upper level it will crawl no matter what speed ..
I do have a metal 321 bridge and girder that the lionel tubular track is laying on I tried to isolate it temp but it did not seem to make a difference..
The Tmcc 624 seems to run better with only 3 cars behind it also I guess it like operating a real loco with me having to throttle up and down..