Unclogging group for unclogging a filter of a pumping group for pumping diesel to an internal combustion engine, the unclogging group comprising: —a metering unit comprising an electromagnetic head and a control valve for controlling the diesel flow; —a filter associated with the control valve made at least in part of metallic material; —a temperature sensor for measuring the ambient temperature; —a control unit coupled to the temperature sensor; —an electrical circuit controlled by the control unit for supplying electrical current to the filter; wherein the control unit is configured so once received the starting input of the pumping group it compares the temperature measured by the temperature sensor with a threshold value, and if the temperature measured by the temperature sensor is less than the threshold value the control unit commands a delay of the starling of the pumping group of a period wherein the control unit supplies electrical current to the electrical circuit connected to the filter.