The paper deals with the optimisation process of existing engines and the compilation of data to allow future electronic control of fuel injection. The general trend is towards the development of high-pressure electronic injection with injection pressures exceeding 1500 bar and with the reduced injection timing.We based our research measurements of diesel engine on the above assumptions. The measurements were undertaken on an engine tester by means of an analyser, charge amplifiers, a needle lift transducer and pressure measuring sensors. Using the measuring instruments we measured the needle lift, injection pressures in the nozzle, combustion pressures, fluctuations of pressure in the charge and exhaust ducts in relation to the crankshaft angle,crank revolutions per minute, preinjection angle and engine loading. Moreover, we measured the fuel consumption, the temperature of cylinders and bridges between valves in the engine. We then calculated the temperature in the engine cylinder and other control characteristics using the simulation programs. The work described in the paper is focused primarily on the complex measurements and their description as well as on the optimisation of the engine along with the production of tables and diagrams illustrating an optimum engine adjustment to individual speeds.With the data thus obtained we could initiate the process of introducing the electronic control of fuel injection.