Help with my Nissan Almera 2004

I have a 2004 Almera and it takes a long time to move forward and the changes does not return them to accelerate I have to stop almost completely so that I return the cameos I just changed the acceleration body and I do not improve anything that because it is then the changes the birds well swim The first to second to second and the other vien In progress I would thank you for having a hand please I wait for your answers thanks