is advantageous in terms of reducing manufacturing costs because it allows the use of the same technological process and equipment to incorporate the two different functional elements into the needle position sensing device if the layer which is used to insulate the first and second bodies anti friction of the injector does not possess the property than a special anti friction layer must be used to coat the shoulder of the cap nut 9 which adds cost the use of a separate washer between the shoulder 10 and the nozzle 5 is possible but should be avoided as it adds another dimension which must be included in the tolerance chain defining the relative position of the nozzle orifices and the combustion chamber of the engine the use of a separate washer also increases the risk of a mistake during injector assembly for instance it can be forgotten to insert the washer which will result in misalignment of the fuel jets in the combustion chamber and poor engine performance the application of the capnut 9 the entire surface of which is covered with the electrically insulating and anti friction layer together with the connector 23 as shown in fig4 for electrically connecting the second body to the ground may allow to further reduce the manufacturing cost by eliminating the operations necessary for masking or.