an injection molding apparatus utilizing an injection molding machine having a pair of separable mold elements forming a mold cavity therebetween and arranged for separation for the removal of the molded product , means for opening and closing the mold elements , and injection means for injecting the moldable material into the mold cavity at a first pressure and for exerting a second pressure on the moldable material as it cures in the cavity . the apparatus provides data acquisition and application in the operation of the injection machine . the apparatus includes means for measuring the separation of the mold elements during the injection of the moldable material , and means for causing the injection pressure from the first pressure to the second pressure upon detecting a predetermined separation known to produce an acceptable product . means is provided for maintaining the second pressure until the thermoplastic material has cured . the mold is then opened and the cured product is ejected . means is provided for detecting and accumulating the maximum separation of the mold elements during a plurality of mold cycles while producing acceptable product . then , a value for the separation of the mold elements is selected based on the maximum measurements accumulated , and means is provided for substituting the new value for use during subsequent cycles to improve product quality for the predetermined separation previously used .