I have trolled around here and not found my issue. Intermittently the auto transmission will shift late. 3 to 4 th is near 50 mph. All shifts are late. I used to shift when I wanted by moving my foot, that does not work when it is acting up. Temperature does not seem to make a difference. One time I drive it works normal, next time it acts up. When acting up it will down shift hard, which is early at a higher speed. Also when in 4th on the highway it does not lock up, unless I push it to increase speed or pull a hill. As pressure is released it unlocks. RPM change of 200 rpms. I took the car to a transmission shop for the lock up issue(someone supposedly good with Honda's). Car in general runs great...
Currently has 206k on clock. Motor was rebuilt by previous owner at 178k

Work done; Temp sensor, thermostat, TPS sensor, speed sensor @ 185k, since last fluid change I added Lucas tranny treatment(made shifting better for maybe 1k miles)

 

Does the S light or the D4 light start flashing when driving? Have you checked for any codes? There is a writeup in the common diy thread on top of the gen tech help forum to get CEL codes.

What did the transmission shop say about your shifting issues?

 

No codes no lights. This model does not have the S light. The shop said it was as good as it would be... They adjusted the linkage which made shifting a little easier/softer. The delayed shifting was not an issue when they looked at the car. Did 150+ miles yesterday. Shifted properly (on the tens) most of the trip. 55mph + so not a whole lot of shifting.

This is why I am baffled, I have talked to a number of people, no one has any suggestions Wishing I had kept my '90 sedan now.

 

So on the ride home I stopped at a light, the trans was acting up, put car in neutral turned off restarted and trans shifted normal almost all the way home!

 

I'd hate to suggest the transmission control unit (TCU) without some testing first. Transmissions are tough to diagnose, so purchasing the same TCU from a u-pull-it yard is much cheaper than replacing a transmission.

 

I thought I had posted this: Changed the TCU and NO change, still have all issues.

 

What year car do you have. Have you tried changing the shift solenoids. That is what it sounds like to me.

 

Or at least cleaning the solenoid screens.

 

1992, I figured that the solenoids were checked when The car spent almost two weeks at transmission shop. While trying to fix the lockup problem... Will look at the solenoids this week myself.