Hello everyone,
I have a serious problem with my '87 260E. Well, when I'm driving without savage acceleration (without kickdown) everything is OK, but when I'm pressing it, the revs are rising up to ~5000rpm ang the car gets "hiccup", jerks

, does not accelerate. The car has also installed an LPG system and everything works fine, so I have excluded troubles with ignition system.
Have anyone got this sort of problem? What can it be? Fuel pump, fuel pressure acumulator?
What values of flow quantity and pressure should has the pump?