Mitsubishi Repair: 1990 eclipse automatic trans, 1990 eclipse gsx, overdrive switch

Question
1990 eclipse gsx 2.0 automatic trans
trans shifts 1-2 good 2-3 good d-od not good just drops od does not slip can shut od off and it will drive around just fine

any help will be appreciated  

Answer
Jeff,
This sounds unique, mainly in the fact that I don't believe Mitusbishi put out the GSX model with an auto tranny in 1990.  But regardless, this sounds like there may be a problem within the overdrive switch.  You should have the switch inspected and replaced if necessary.
Good luck!