I started having shifting problems as it would shift down to the lower gears off and on and then stay there a few months ago. The car sat in my drive until I could afford the parts. I changed the fluid and the speed sensor on top and just recently changed both shift sensors under the car. I had been driving my old truck to get around until I could afford the parts so after completing the job I drove the car today. It worked fine had no problems shifting in and out of all the gears and I felt that I had really accomplished something and that was a great feeling until after about 3 hours of driving in town. After that as I was driving up the highway it happened, my car shifted down violently then up then down to second gear and at one point it acted like it was in neutral then it kicked into second and I barely made it home. I would appreciate it if someone would let me know what they think it is. like an electrical problem or what it may be. Thank you.

 

Have you checked for any stored codes?
Verify that the ECM memory fuse is also not blown.
Next backprobe the TPS, if this is faulty it may cause erratic shifting, no shifting and often times no code being set.
Find a long on ramp during low traffic and floor the throttle, does the car upshift through the gears while at WOT? If so, most likely a TPS issue.

 

Thank you Mike, But help me understand your alphabet explanation. I am really green when it comes to working on Honda's I think you are referring to the Emission control module (ECM) if am i not mistaken? And where can i find that fuse? And please tell me what the TPS is and where i can find it? Does any of these items have any thing to do with the Automatic Transmission Control Module going bad?

 

I should have wrote, ECU, Engine Control Unit. The brains of the beast. There should be a two wire blue connector above the passenger kickpanel. Jumper it and turn the ignition to II(ON) and the CEL light or D4 light will blink any codes if there are any stored.
On a 90-93 'CB' Accord I think it is located in the engine bay fuse panel.
Throttle Position Sensor. It is the sensor located on the trottle body shaft opposite side of where the throttle cables are located.
The TCU should not go bad because of these items being faulty, but if the items in question are giving out bad data, ten the TCU will not command a shift event at the anticipated time.

Click on the 'techato' link in my sig, muc more indepth information for your troubles. Start at 'ecu' with the four steps, look for any codes, then move on to 'transmission'.

 

Thank you Mike for the info. I will have to wait awhile to get into it, I am down right right now with the flu. But i will check it out as soon as i can. Thanks again.