no thats a little high, I test drove a 91 integra with an auto for my little brother and took it out on the freeway and it was running the same rpm's as my 92 rs 5 speed, it was at 3200 rpm's at 70 mph. It sounds like 4th gear might not be going in or not locking up????? Solenoid???? Valve body????? TCM (tranny control module) Have a good tranny shop look it over for you.