4T60E Tranny troubleshooting.

hello, im new here in desperate need of help!95 grand am 3.1 with 4t60e tranny has 126000 miles. tranny shifts fine sometimes then other times wile im accelerating it slips, rpm's fly up and it takes 10 sec with foot off of gas for it to catch( almost like its in neutral). Problems getting worse with time. Only 2 codes ignition switch( Which i replaced so i think the code is old) and vss which i replaced yesterday, vss made no difference and mph gauge is still jumping around reading crazy. fluids are good. I think there is a vacuum leak somewhere i could hear it. When I first put it on the road 2 months ago problem wasn't as bad as now. At 60 mph it would vibrate violently. I unplugged the main plug on top of tranny and vibration stopped, I drove it for a day like that until I learned it was not shifting at all then I replugged and vibration is mysteriously gone but still have a very bad slipping problem. I think the car starts in 2nd gear. Any advice would be great, thanks... Does anyone have a diagram of the vacuum lines threw out the car?? Is there a way I could disable the tcc silonoid to check for that??

Welcome to AF and sorry for the late reply!!

First I'd find & fix that vacuum leak, could be causing your troubles.

Also had the car been sitting for a long time and not driven ??
If so, I'd try a fluid & filter change to see if that helps.

I'll see if I can find this link to a transmission site with testing procedures so you can test the TCC, it to might be the culprit. You might need to take it to a trans shop and let them scan it for codes.

Found these two links that might help.
http://www.atraonline.com/manuals/general/tetdv/tetdv-c3g.htm
http://autorepair.about.com/cs/doityourself/l/aa011703a.htm

Hope that helps !