Rough and acceleration is poor while driving. The problem seems to be when the RPM is at about 2500. Any solutions for this problem?
No solutions are forthcoming with the tiny bit of info you gave us about your car.
Is the check engine light on? How many miles on it? Engine size? Have you had a mechainc look at it? Are you going to fix it yourself? How long has it been doing this? Does it use a lot of oil? Coolant?