Abstract: A pre-plasticizing injection molding machine includes a plasticizing and flow regulating assembly connected to the tip of an injection chamber or shooting pot having an injection cylinder. A distributor valve allows the transfer of plastic resin into the shooting pot at low pressure and prevents the backward flow of resin to the plasticizing unit when the injection plunger injects the resin. A plurality of distribution channels in communication with either the distributor valve or a separate valve, and having outlets in the shooting pot angularly equispaced in proximity to the perimeter of the conical tip of the plunger uniformly distributes new resin behind resin retained in the shooting pot from the previous injection cycle, thereby obviating stagnation zones.