how do i know if my transmission is going out on 1991 Acura Integra

my car is not able to go over 30 miles per hour but all the geers go in good

1 answer
It could be for different reasons, like a clogged catalytic converter, restricted air intake, etc...
Better to take it to a repair shop and ask for a diagnostic. They will be able to pinpoint the cause, this way you don't guess and replace unnecessary parts.