Hey guys, I got a 93 FD3S, everytime I start the engine, a few minutes later, the rpms become unstable!! And I shit to any gear but 2nd it gets worts!! Also I just can get to 6000 rpms! I forgot to tell you when I shift to any gear I don't let go the clutch and the rpms get lower and more unstable

Could be many things but first thought would be to check the throttle position sensor. Instructions would be in the Factory Service Manual. That's available as a download in the FAQ sticky thread in the 3rd Gen. Technical Section. Page F-168

I can't attach videos!? I could send the video!! It's pretty odd what happens when I shift! If the air pump isn't working could that interfer in anything?

You don't need videos.
Go to the 3rd Generation Technical Section and download a free copy of the Factory Service Manual. Then follow the instructions to check your throttle position sensor or do any other trouble-shooting.

Any history on the car? Recent mods? Or Did it just start doing this out of the blue? Or is this a new car to you?