I have a 1990 4runner which has been sitting for about 3 years. I just decided to get it going again so I replaced the fuel tank, fuel pump, and fuel lines. Also changed all the fluids and the water pump and timing belt. Changed the spark plugs and installed a new battery. It started up and runs like a champ. I took it out to drive and the transmission is now shifting very weird, it will not shift until I hit about 4,800 rpms. Please if anyone has delt with this before let me know.

 

Probably just blocked filters in the transmission, have the auto box serviced ( or do it yourself if you can ) .

 

You can easily determine whether the problem is mechanical or electrical by doing a manual shifting test as described in this link...

http://personal.utulsa.edu/~nathan-b...33manualsh.pdf

The test is easy do to, and will help diagnose the problem.