My 1989 Honda Accord LXi 2.0l (207K miles) will not shift from 1st gear when the engine is cold. Sometimes using D2 or D3 will cause a shift. I have replaced fluid with Honda specified and added half bottle of Lucas Transmission Treatment. After the engine warms, it will shift but roughly through gears 2 and 3 and again upon deceleration. Speed sensor replaced w/ one from junk yard. No visible leaks of tranny fluid. Please help if you can.
First of all you should know that Honda is particular about it's transmission fluid, so I would not recommend adding anything but that.
It sounds to me like there may be an issue with your seals. I say this because it seems to shift after the engine warms up. What can happen is that if the seals get contaminated they swell up. Once the engine is warm however it allows fluid to move through.
It's also possible that you have a stuck valve in your modulator.
I would recommend that you have a transmission shop take a look at it and diagnose your problems so you don't put money unnecessarily into the transmission. Hope this helps.
〉 Answered on Oct 4th, 2008 by Lori Johnson, Owner and Instructor at Ladies Start Your Engines