Failure of an idle air control valve in a gasoline-fuelled automobile

The functional failure of an idle air control valve in a gasoline-fuelled automobile in India has been analyzed. It was found that the failure was related to the formation of deposits inside the idle air control valves. The deposit was found to contain both organic and inorganic constituents. The deposits were characterized using a variety of techniques including chemical analysis, optical microscopy, FTIR spectroscopy, GC–MS, X-ray diffraction and thermal analysis. The possible source of the deposit formation has been analyzed. It is inferred that the cause of deposit formation and the subsequent failure of the idle air control valve is because of the back flow and condensation of fuel vapor combined with contamination through extraneous dirt especially silica from the air intake system.