The ignition system and the spark plug itself are comparatively simple constructions. The spark plug itself, if properly observed, and if signals from ignition system components are properly analyzed, may represent the best ‘’sensor’’ on the engine. Considering their very position and manner of operation, spark plugs and ignition systems represent the best source of information about what is happening in the cylinder and what kind of combustion we are having.
Following a short theoretical part, diagnostics is performed of the different ignition systems. Analysis of oscilloscope signals and obtained results.
It is possible to easily detect different problems in the system of ignition, injection and also of mechanical nature without the need to disassemble the engine or components, by simple measurement of signals and their proper interpretation. Problems with cables, ignition coils, spark plugs, too rich or too lean mixture, lack of compression, cooling problem can simply be detected if physical operating principles are known and if there is an understanding of the values which can be easily and quickly measured.