trans issue

so i just started having a problem with my trans
i figured it had to do with my nss
so i rebuilt my nss and now i have reverse lights and all that good stuff
now my trans when i put it in drive feels like its starting out in second gear
when i mash the gas i move up speed at snails pace
but i can manually put my trans in first and move up through the gears and the trans does fine
i replaced the tcm and still no luck
also i checked the trans fluid and its good
anyone have any ideas?

Did you adjust the throttle pressure cable? http://www.naxja.org/forum/showthread.php?t=1015963

Have you tested the TPS?

If you disconnect the TCU and shift manually, do you get 1st in 1-2; 3rd in 3; 4th in D; reverse, neutral, park? If so, the electronics are the problem. If not, your issue is mechanical/hydraulic.