Heterogeneous nanocarbon materials including both diamond and graphite phase domains demonstrate enhanced efficiency of electron emission that often remains unexplained by theory. Characteristic features of the actual mechanism of facilitated emission were searched for via position-resolved investigation of emission current fluctuations. The reported studies were performed with nanoporous carbon chemically derived fromsic. Partially ordered and spatially correlated character of fluctuations observed in the experiment allows to presume involvement of self-sustaining non-stationary electric field as a possible factor of emission enhancement.