1997 Jeep Grand Cherokee Tsi Tranny Problem

I recently purchased a 97 Grand Cherokee Tsi and all shifting is good except when shifting into 3rd gear it refuses to shift from 2nd to 3rd now reverse neutral park and drive shifts from 1st to 2nd but then wont shift any further. Im 17 and only make about 650-700 every 2 weeks so cant afford a new tranny or a rebuilt one is there anything else i can do? it is a 4.0 straight 6 and an automatic tranny

1997 Jeep Grand Cherokee Tsi Tranny Problem