When a jedi is behind you run to sarlacc and push him in with the speeder
or let him drop from the kamino bridges (just with a nade, they'll fly high in sky and land in sea)
Basicly its best to let nades bounce from the wall under them (they only get nades that are directly to them) or just near them
However, i hardly played with jedi (maybe once) in MP and i'm grateful for that