I had similar problem w/ mine not shifting. Re adjusted the bowden cable and that seemed to change things..not bad, not good. Bit the bullet and took it in to local shop to at least change fluid and filter (clogged was the suspsect). The called w/ good news bad news..good news is that the transmission fluid was clear. Bad news was that almost 1/2 of filter was sucked up into valve body. Good news is that after extensive cleaning, the car now has another 4000 miles on it an shifts like a dream..check your filter!