My 1992 Mazda MPV van will not go into 3rd or the higher gears it starts to slip

What is your question?

I have done a tranmission fluid and filter change and still slips. First gear it has all the life as new and second. Could it be the siloniods? in the transmission it sat for 7yrs. The fluid that came out was dark didnt smell like burnt yet not just tranny fluid. Stumped