Hi, I have a 1988 Toyota 4Runner with a 4 cyl. engine and an automatic transmission. I purchased it from my nephew about 20 years ago and it ran great for about a month before the engine started slinging oil everywhere. I was disgusted and towed the vehicle home and let it sit, and sit, and sit. Recently I had the engine rebuild and have replaced countless items and finally it's back on the road. ( with a lot of help from all of you guys on yotatech). My problem now is the transmission doesn't want to shift properly. Before sitting up it shifted perfectly but now it shifts late and sometimes hard. I changed the fluid and filter when I got the 4runner back on the road. First and second gear does good but the higher gears are the problem. After searching online it seems the solenoids in the transmission may be bad which sounds logical since it did sit up for so long. Would this actually cause the transmission to shift hard or late? When it's time for the transmission to shift you can let off the accelerator and it shifts better. Should I replace the solenoids or maybe try some type cleaner in the transmission first? What would you guys recommend? Thanks When I first started driving the 4runner the transmission shifted better than it does now although in the past several weeks it doesn't seem to be getting any worse. Any advice is appreciated.

 

Tells us which transmission you have. It's on a sticker on the door pillar.

If it's a A340, shifting into overdrive is suppressed when the engine is cold. You could have a problem with the ECT sensor.

If you have an A340, an open/shorted solenoid (though not a stuck one) will throw a code.

 

It's a A340H transmission. I'm not receiving any codes. The transmission shifts the same whether the transmission is cold or warm. I don't have a tachometer so i'm not sure what the RPM'S are when it does finally decide to shift but it's higher than normal. Before it goes too high I let off the accelerator and it changes gears. If the ECT switch, that is located on the console, is bad, would it cause shifting problems? I have to press it several times to get it to operate.

 

Totally normal. Mine does it all day in cold weather even on the freeway. Once it warms up outside the shifts are better.

 

ECT: Engine Coolant Temperature,

You may thinking of the Pattern Select Switch, which just delays shifting to higher rpms.

 

^^ Toyota also called this ECT for Electronically Controlled Transmission (NORM or PWR modes), just to make things confusing....

When you say you have to push the ECT switch several times to get it to work, what do you mean?

 

 

Pwr side/mode grounds an input to the transmission control. This could have rodent damage or got pinched and shorted somewhere. Another factor would be improper adjustment on the line pressure cable at the throttle. It seems to respond to the tps signal, you'll want to check its signal levels (procedure in the FSM) from memory with ect in diagnostics mode it will output the tps position as a 0-5v signal on the ECT diagnostics wire..

Your switch's are likely sticky clean them but it's only important that the pwr one works if the pwr indicator light isn't lit its in normal regardless if the dash says normal or not, again it just grounds one input otherwise that signal wire is left floating.

 

Old87yota, When I said I have to press the switch several times to get it to work, what I was refering to was the switch will not stay down. I keep pressing it a few times before the power light will stay on. If I hold the switch down with my finger the light stays on everytime but when released it does not want to stay down. I think my best option is to just replace it if I can find a good one. Wallyto, That's the switch I was refering too. Mine looks a little different but probably just difference in the year it was made, mine is a 1988. CO 94 PU, I'm thinking the same thing since the vehicle sit up for so many years and I live in the south where the moisture is bad on everything. When the switch does stay in the power mode the transmission shifts hard and the rpm's are very high before it goes into the next gear. I know part of this is normal but it seems bad on the transmission for it to shift this hard. When in the normal mode it shifts smoother. Some gears you have to listen closely to hear it shift while other gears shifts better than it does in the power mode but as soon as it shifts the rpm's rises quickly before going into the next gear. It seems to be getting better just by driving it so i'm hoping the problem will take care of itself. Should I use any type of cleaner in the transmission since it was sitting up for at least 15 years? The fluid and filter has been changed twice recently?

 

Take the switch out, spray with electrical contact cleaner, actuate it, repeat untill the flush comes out clean and the switch holds position. Don't remember how it comes apart, but if it is obvious relube it after.

While it is possible the clutches are slipping since you changed fluid, fresh fluid is more slippery, it sounds like you are just noticing the torque converter lock/unlock.

Do not use anything to "clean" the transmission, that stuff is evil, if you really think it needs "cleaned" it actually needs rebuild flushing it with solvents or stopleak crap is just going to kill it.

 

^^^ what he said. Don't trust VooDoo in a bottle. Check your kick down cable adjustment. Since you recently did the engine rebuild check everything that was touched during that work before you carry on with other possibilities.

 

Sorry for not responding sooner but I have started working 7 days a week and haven't been online much. The transmission seems to be getting better the more I use it although the front seal has started leaking. It was changed when the engine was installed and didn't start leaking until recently. Does an automatic transmission happen to have a vent that may be plugged causing it to build up an excessive amount of pressure? I have about 2500 miles on the recently rebuilt engine.

 

One of my friends used to say:::'Lack of use is worse than abuse'. But he died.