trans. shifting

[scottm0821]

this might be a little long, bare with me.
yesterday i had a injector changed out. cranked the truck up and took it around the block prolly 5 miles, came back and put my sct back on a spartan tune. i went for another test drive and for some reason when i would pull up to a light it wouldnt downshift until i was taking off it would slam down a gear, also it was flairing really bad between each gear. the only thing i noticed abnormal was while tuning the truck i saw on my radar detector the truck only had about 9 volts from cranking for awhile after the injector change.
So i pulled over put it back to stock and it drove fine. This morning i put it on a canned tune and it did the same thing so i drove a little bit and it got better so i decided to try and switch back to spartan tune. and for some reason it was flairing real bad again and would not shift into 5th or 6th which ever one. i got to 50 and it was running about 2500RPM. so i stoped and put it back to a canned tune, still flairing really bad and acting weird in O/D, so i put it back to stock and its better but flairs really bad from 3rd to 4th and when it flairs it slams!! into the next gear hard.
Any ideas? why would it grandually get worst??
Also it sat for about 3 weeks before the injector got changed. and before i parked it, that day i noticed it was taking awhile to change gears. and it is still taking awhile.
Right now its in the drive way on stock with the lights on and batteries unhooked to see if that will do anything.

[scottm0821]