This paper devoted to pollution of the atmosphere due marine diesel engines in operation. In the paper presented are results of the investigations carried out in the Gdynia Maritime Academy laboratory with the use of a ship diesel engine, one-cylinder, two-stroke, crosshead of longitudinal scavenging, which was loaded by means of the water brake. This diesel engine combusting heavy fuel oil IF 40. The test-involved effect of two selected control parameters of fuel injection system ship diesel engine: fuel injection pressure and injection advance angle. Both selected control parameters were changed during the experiment separately, each of them three times. And so: changing the fuel injection pressure - for three selected values: 18, 22 and 26 MPa; changing the fuel injection advance angle - for three selected values: -10 centigrade, -13 centigrade and -16 centigrade before the piston's top dead centre (BTDC). The measurements were performed within the wide range of engine load at the permanent rotational speed of 220 rpm. For each of the above selected values six measurements were performed at the following engine loads: 25%, 40%, 50%, 60%, 70% and 80% nominal loads. Control parameters to change the injection pump and injector engine, during operation of the engine, by means of a supplementary-scaled instrumentation of the injector and injection pump. Owing to this is was not necessary to stop the engine before each successive test cycle. This way of realization of the measurements guaranteed running them in steady conditions. The elimination of influence of possible disturbances witch could arise from multiple starting and stopping the engine improved accuracy and reliability of the obtained results.