The paper attempts to determine the impact of fuel impurities on the spark discharge energy and the wear of the spark plug electrode. Spark plugs were analyzed in two typical configurations of the ignition system. A number of tests were conducted to determine the wear of the spark plug electrode exposed to different types of impurities. The spark discharge energy for new and worn spark plugs was determined through calculation.
The paper discusses the modelling of magnetic coupling in ignition coils by fractional differential equations. The use of fractional-order coupling allows us to consider the losses caused by the non-linearity of the ferromagnetic core of the ignition coil and obtain the waveform of the ignition coil’s secondary voltage closest to the values obtained experimentally.
The paper analyses the possibilities of treating the ignition cable in the internal combustion engine as a distributed parameter system. It presents the experimental verification of computer simulations of signal propagation generated by ignition systems in the ignition cables, modelled by the distributed parameter system. The tests conducted to determine the wave parameters of ignition cables, as well as the results of numerical simulations and their experimental verifications, are presented. It is concluded that the modelling of the ignition cable by means of a long line gives positive results that can be used for the design of a spark plug with impedance equal to wave impedance of the ignition cable.