Firestorm128d

My father in law has an 88 4runner 3.0 with the automatic transmission. Bout a year ago the Over Drive apparently quit working. The light will not come on on the dash and it does not seam to engage either. Now more recently it is shifting all funky. It seams to skip second gear and go right into 3 dog down and stay there. If you floor it hard it will drop into first for a sec and then blast right back to 3rd. If I shift it manually it seams to work OK. I am guessing the valves maybe? I don't know diddly about automatics. He wants to sell it and its a hard sell with this problem. Anyone have a best guess as to a probable cause and rough cost for repairs?

motocrossaddict223

I had this problem while i had my auto, first things first, change the filter, then add some lucas auto transmission additive. Now if that doesnt fix it, i cant remember for the life of me what your issue is called but, you'll need a new tranny. Now for the overdrive, see if it's plugged in first, clean the connectors etc. If the light still doesn't come on, its a computer issue, that could also be your shifting issue. I switched out my computer for a junkyard one and it solved all my issues. If he wasnt selling it, id say just swap a 5 speed, i did and its awesome. If you want to switch out your transmission computer, and cant find one in your area you can pm me, i have one left over from my swap.

Firestorm128d

Thanks for the info. He had someone do the filter, and he has tried the lucas. If it's possible that a toasted computer can cause a shift timing problem I would love to try a new one. I checked all the connectors, cleaned and dialectic greased them all. Inside the module I saw some resistors that looked like the have seen some hot days. Noting I could scope though so i put it all back together. Its worth the try, what do you want for your old module?

motocrossaddict223

Sent you a PM.

maco35

Start by adjusting your TPS, that cured the shifting problems i had with mine. www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

motocrossaddict223

yea i agree, i would do everything thats free first, why spend money you don't have to

4runnerx3

You need to unplug the ECT and do a manual shift. The ECT for the tranny is under the console under the radio. If you're skipping a gear, that's a sign of a bad shift solenoid. With the ECT unplugged, L is 1st, 2 is 3rd, and D is OD. You will not have 2nd gear because the solenoids are disabled. The OD light will blink a code.

Ground square plug



switch ignition on













Shift solenoids work in a pair, off and on

1st gear- solenoid 1 on, 2 off
2nd gear- no. 1 on, no. 2 on
3rd gear- no.1 off, no. 2 on
OD- no. 1 off, no. 2 off