I've already post a message like this but the answer received didn't fix the problem (thanks for your answer)...
Every thing is ok with the 734 but after setting the autopilot and the FMC, i've to turn on the engines, till now all ok, first the number 1 then the number 2, but when i want to taxi just on trottle works the 1 or 2, so i press E+1+2 but then agian the 1 or 2. I've tried everything E+2+1, turnig on the ATC and then agian E+1+2 (this works in the other fs2k2 planes but not in this) please i need your help and i don't want to re-sync them with the mouse, nor using Ctrl+E to turn the engines on.

Thanks