ramrugby09

Ok guys this is where I am now. I pulled the pan on the transmission and pulled each solinoid. I tested each one per the FSM all of them work perfectly. Then I removed the valve body and made sure that none of the valves were sticking.....all good there too. I did replace the o-rings on one of the plungers above the valve body but every thing inside looked perfect and new (just rebuilt 9 months ago). Now I have got her all put back together with a new screen filter. Of course when I drove it the same problem occurs. I have noticed in the past and yesterday sometimes when I try to start the truck I'll turn the key and nothing will happen. But if I but the gear selector in neutral it will start. Itwill start in neutral all of the time now. Is that right? Could this have anything to do with my Over Drive problem? Again the overdrive always seems to be on. It is fine until you get to 35-40 miles per hour then it prematurley shifts to overdrive and boggs untill you get to 60+ miles per hour. I replaced the lights in the O/D light to see if it was blinking but nothing. When I hit the O/D button the light goes on and off but nothing happens. Could this be my ecm for the tranny? Oh and by the way its a 86 4Runner, where do I put the jumper to see if there are any tranny codes stored? Basically I think that I have some sort of electrical problem but what do you guys think?

regularguy412

Look here for more info:

http://personal.utulsa.edu/~nathan-b...autotrans.html

If you know which transmission you have, there are troubleshooting guidelines.

Mike in AR

ramrugby09

Its A340H, I'll check that out.

kt19

Did you check the button? Does it downshift if you put it to the floor? Is the throttle cable correctly adjusted? (The one that goes to the tranny)
If you are unsure of any of the three I would start with those. I don't know for sure but I've been told that the light and the signal to the transmission are two different circuits on that O/D Button. (A double pole switch) Also you may want to verify that the gear selector is properly adjusted and positioned bases on you trouble with the starting.

ramrugby09

I checked the cable and adjusted it. I havnt checked the button, but like I said it does turn the light on and off. I will check it with the volt meter. And sometimes it downshifts when I floor it but 7 out of 10 times no.

InternetRoadkill

If the thing is only wanting to start in neutral, but not in park, then you might check the neutral start switch adjustment. The switch itself might be bad too. Either way, it could be causing your problems since it is what tells the computer what gear has been selected.

regularguy412

Believe it or not, the TPS may be out of adjustment. The throttle position has a lot to tell the transmission about supposed engine load. It does provide input into how the transmission shifts.

I think it's worth a shot to check it for proper operation and adjustment.

Mike in AR

ramrugby09

Thanks for the input. I'm willing to try anything at this point. I'll try the throttle position sensor and see what happens. Then I'll try the neutral saftey switch. Don't worry I'll let yall know how it goes!

InternetRoadkill

One more silly thing to check while you're underneath is to make sure the shift linkage is adjusted correctly and that the rubber bushings are in good condition with no slop. Any slop will cause the tranny to sit in between gears.

ramrugby09

Ok, this morning I pulled the throttle body and adjusted the TPS. Damn, it wasn't even close to right. So now that I have done that; the truck idles and runs much better. It has mostly gotten rid of the bog at 35 miles per hour. It feels right but to tell you the truth I'm not sure what right is anymore. Anyway I'm better off now than I was so... I also checked my engine codes and there were numerous codes popping up so I pulled the fuse to reset it. I checked it again after setting the TPS and driving to work, no codes popped up. I am still having the O/D problem so my guess is to start with the switch and go from there. Oh yeah does anybody know where to put the jumper wire to read the transmission codes on an 86 4Runner?

ramrugby09

Ok this morning I rode to work with the electronic speed sensor disconected. There was no change in how the truck operated. Could this be bad and causing my bad shifting? I tried to test it yesterday by jacking up one wheel and reading the ohms. When I spunthe wheel it wouldn't register until the wheel had spun several times, it would register for a split second then nothing again for several more spins. Any ideas?