hi folks i am working on a 92 4runner for a friend. It is scipping 2nd until warmed up and once it it is warmed up it will not shift into overdrive unless the od switch is off. And once its in od it does not drop out with the swicth. I have checked the switch and the wireing splice in the engine compartment and they both check out good. The next step as of now would be changing out shift sileniods. If somebody could please help I am trying to keep his cost down.
intermitent overdrive on 1992 Toyota 4Runner
It sounds like your trouble shooting technique is correct. It does sound like a solenoid or something more serious in the transmission. How does the transmission fluid look and smell? Perhaps if you have nothing left to loose drop the transmission pan change the filter and clean the pan (inspect for debris) refill with fresh fluid ans even try disconnecting the trans cooler line get some one top up the fluid as you run the transmission just to get more fluid out. I don't like the transmission flushing machines on a trans that might already have problems.
thanks autotechpat, I have already dropped the pan and found nothing. the fluid doese not look or smell burnt. I thought I would possibly find the harness grounded out in the pan but nope. I also changed out the ecu with a good barrowed one and nothing changed. I think we are going to chenge out the 2-4 solinoid and see if that fixes it. I realy dont want to start throughing parts at it but at this point what left?
The following link gives a good explanation of the conditions needed for the transmission to go into overdrive. http://www.autoshop101.com/forms/h16.pdf I have replaced all 3 solenoids in mine and it fixed most of my problems, but I still don't have overdrive. I think my problem is a stuck valve or a faulty temperature sensor. Overdrive requires both solenoids to be off and a valid temperature range. One other possibility could be a bad or poorly adjusted throttle position sensor.