Honda accord 91 automatic will not shift right.

transmission unit is faulty, check it

Definitely not good. The transmission is slipping internally due to worn gears and clutch packs. It will have to come out for rebuilding, IMO. Have a transmission shop check it out.
Good luck.

That is the shift indicator it wants you to shift if its an automatic make sure you are in D (drive)

The transmission is probably the problem. If it is going over 3,000 rpms it sounds like it is not shifting right. I would check the tranny fluid level. And see how dirty the fluid is. If the fluid is real dark it is burnt and needs to be changed with new filters. If that does not fix the problem your torque converter is going out. Thanks

Your transmission is probably jumping in and out of "torque converter lockup". The lockup is the most efficient mode because 100% of the power from the engine goes to the wheels and is not lost in the torque converter. It only goes into lockup at higher speeds, but will jump out if the computer senses it needs more power (at the higher engine RPMs) to maintain or increase your speed. I recommend either going faster or slower if this is bothering you. :-)

you could be running low on fuel pressure due to a plugged filter, do a fuel pressure test

you need to check your transmission fluid. Its a possibility that your transmission is going.

check fuses or see if something might have got jamed in the track and also try movin the part where the seat belt moves back and forth to see if the motor is dying

try cleaning the throttle body.

you are losing your transmission..you need to get it to a shop and have it checked