im working on my 1986 4runner. it has the 4 cylinder engine. the transmission has never shifted properly. now for the problem.

when i first got it, i could hold it to the floor and it would still shift extremely quick. i would be in overdrive by 20 m.p.h. i just dealt with it and manualy shifted by hand. now all of the sudden it wont shift until (im guessing here, because i dont have a tach) about 5000 r.p.m.

i looked at the tranny and it looks like all of the wires are hooked up, i changed the transmission computer, and the fluid smells fine. the only thing i can think of is there are some wires on the motor that have never been hooked up, but that is the way it has been since i got it. i would hook them up, but i think someone has put in a newer motor therefore there is no place for them to go.

any ideas? thanks in advance

 

Here is a shifter that will bypass the computer and costs $80. If you hook it up and works fine then you limited the problem to the electrical. Then you can try to fix the electrical or just keep using the sifter. If it does not work then it is in the transmission.
http://radesignsproducts.com/contactus.aspx
In my sig there is a link to factory service manuals, they should have wiring diagrams that you may find useful.