New diagnostic methods of alternative LPG/CNG injection systems

Diagnostic methods of gas alternative feeding systems were presented in this paper. Methods of validation for properly cooperation between OEM petrol systems and gas injection system were described. Procedures allowing the analysis ofproper operation of both petrol and alternative feeding systems were presented. A detailed study has been done on seąuential injection system, as a solution fulfilling restricted requirements of new SI engines. Obtaining both satisfactory emission reduction level and minimal power drop for alternative engine gas operating is only possible with all diagnostic procedures especially ones connected with system prototyping phase being done with high precision equipment characterized by low inertia of transducers. Sensors output signals reąuire acquisition with the use of more complex and faster systems. Proper choice of test equipment at each step, guarantees repeatability and what results also reliability ofrealized diagnostic procedures. Influence of alternative gas fuelling systems on mixture adaptation, transfer function, diagnostic methods for prototyping phase, diagnostic procedures for alternatively powered vehicle operation, diagnosis of sequential gas injection system during normal system maintenance are presented in the paper.