missing acceleration

Hi! I have a Honda Civic 99 automatic transmission bought recently two weeks before, i
normally drive it every day and while in the begining of my driving almost after a few
seconds drive, my car starts missing although i have already pressed the accelerator
paddle almost maximum but the engine acceleration goes down and it cough while
driving and after few strokes it goes normal till i switched engine off it won't disturb
during the continious drive but on next start it goes the same again and again. Engine
oil transmission oil and spark plugs already changed anything else that can help me
getting this thing out of my way???  Thanks