Kia Pride Problem 1998

I have a Kia Pride 1.3 Year 1998, which is preventing the following problem.
The vehicle in 1 march no problem, but when it passes to the 2nd Marcha this one, it is necessary to accelerate it so that it does not.
This happens alone in 2nd. This car was burning oil so I changed the valve seals, which took one problem less, I was also drooping steam, so the admission and cleaned it, realizing that it had a small fit of refrigerant liquid towards the cylinders, which I also repaired.
I also clean the EGR if I'm not mistaken. But still continues with the problem.
If someone could give me any clue of what may be happening I would appreciate it.