Help ... Ford Fiesta you have the balls full

Ford Fiesta 97 Motor Zetec 1.4 16v ...
The problem is that when I accelerated and loose the accelerator and falls on revolutions it falls so much that most of the time it goes out. When the clutch falls from revolutions, turn and falls for revolutions, it has hydraulic direction. The slow march valve is going to disconnect it ys. The car has annulled the return of the ramp, for more pressure I think. The scanner does not throw failure even if it caught my attention that the progress in idle varies too much, sometimes 64 degrees sometimes -1. Please help