Seat Cordoba noises

Hello, how about someone can guide me, I have to fix the change box of a Seat Cordoba, it has a noise when putting the third as when we fail with the clutch as if the gears scrape with each other, then it is removed, they have told me that it could be synchronizers, and also another problem is that it sounds as it is impaired as if the order of ignition was bad, the motor discharge? I would like to know what could be working badly, I will also disassemble the box, but the problem of "decarburacion" I do not know what to do to isolate the problem. Could someone give me indications?

Thanks

GUSTOVO GUSTAVO

The box is synchronisator but all the time, the decarbonation must be checked, the first thing is that you have no leaks in the escape, if there are you have to solve before carbure

Thank you Kike Mira, it is 94, it seems to me that it is Clx because there is a more modern SXE version that brings the 1.6 monopunto mk3 golf engine, this brings one 1.4 monopuntant too, I did not remember it but found this photo attached on the Internet and is the same.