89 Accord LXi shifting problems

[harbormom4]

Our 89 Honda Accord LXI isn't shifting right. When it's cold it shifts fine. Once it gets warmed up it starts to slip in and out of gear. The rpm shoots way up for no apparent reason and eventually it won't go into any gear and I have to shut it off. I can turn the car off and then back on and it shifts into all the gears just fine for a little while and then they start slipping again. Already checked the tranny fluid and it's good. Shifter isn't loose or sloppy. Could it have something to do with the transmission control unit? Since it seems like everything resets after I shut it off and restart. How do I troubleshoot this??

[gixxerson08]

I am also having the same prob. Started yesterday...

[Oldblueaccord]

We have a service manual to dl here on this site somewhere.

Just a few guesses. If you can find the control modual unhook it and see what the trans does with out it.

I know on the 4th gens I could unhook the TCU and drive the car manual shifting between 1 2 3. If you left it in D it would try and start in 3 and slip alot.

wp

[Dr_Snooz]

No TCU on these cars. The troubleshooting procedure for a 3g transmissions is pretty much the same, no matter what your symptoms:

1. Check the oil level and condition. The oil should be a nice cherry red and not smell burnt. If it's dark, change it.
2. Check the Throttle Control Cable. This tells the transmission when to shift and at what RPM. These can be difficult to get right and can cause all kinds of fun if they are wrong. The manual is available here and directions for adjusting the cable start on p. 15-90. Adjust it to the manual's specs for a start and when you find that you don't like that at all, do it the old-fashioned way: tweak it in one direction or the other and go for a drive. Repeat the process until you are happy with the shifting.
3. If the symptoms persist, take the car in for a flush. These usually run $100 or so, which is a lot cheaper than step #4.
4. Replace/rebuild the transmission. This is the most difficult step. Replacement transmissions will mostly come from junkyards. They may or may not be in any better condition than the transmission you have. Rebuilding is a slightly better option, maybe. These were exceptionally well engineered transmissions delivering good performance and trouble-free operation for 200,000-400,000 miles. They are so well engineered that by the time they begin exhibiting symptoms, they are almost always, evenly, perfectly and completely worn-out. The manual has detailed directions for what areas of the transmission to inspect for wear. Expect every single area to be worn and out of tolerance (ie: should be replaced). You can't buy new parts and used parts will not be any less worn. Your final rebuild will be a big compromise and will probably be a mish-mash of the least worn out parts you were able to find. Nevertheless, it will run fine with few, very slight issues. Expect the whole rebuild to run somewhere between $600-$1,000.

4b. Swap the sluggish, power-sapping auto for a stick shift. The swap instructions are here. Additional, very helpful notes on the swap are here. Note that finding working manual transmissions is getting to be nearly as difficult as finding working autos, so be prepared for some work and wait.

I suspect your specific problem is in the valve body somewhere and that you will progress all the way to #4 for fix it. I would guess that something has broken off and clogged up some important valve. Whatever you decide to do, I hope you at least open it up to find out what went wrong. Take lots of pictures of it and post them here so we can see.