I have an early '86 auto, with Autoauthority clone chips. My 1st to 2nd gear shift occurs at 5000 rpm floored, even when manually shifting. 2nd to 3rd and 3rd to 4th happen at 6300 rpm. I have tried tensioning the cables but it still happens. Does anyone have any ideas?

 

Check the line to the trans for vacuum leak (with a midi- vac). It might leak on the line and/or the modulator that the line connects to may not hold vacuum. It should hold solid and not bleed any at all. Mine did, replaced it and my shifts went from 5100 to 5600.

 

Thanks for the advice, i need to go through the vacuum lines.