i'm practicing b hopping in crossfire, and when i take damage and input impulse 101 into the console, it doesnt do anything even with sv_cheats 1 on. it might be that im doing it on a private server, but i dont know.

You need to reload the map after turning cheats on, so:
1. "sv_cheats 1"
2. "map crossfire"
3. "impulse 101"