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A laboratory wear test is used to evaluate the wear protection properties of new and used engine oils formulated for FFV service. Laboratory-blended mixtures of these oils with methanol and water have also been tested. The test consists of a steel ball rotating against three polished cast iron discs. Oil samples are obtained at periodic intervals from a fleet of 3.0L Taurus vehicles operating under controlled go-stop conditions. To account for the effects of fuel dilution, some oils are tested before and after a stripping procedure to eliminate gasoline, methanol and other volatile components. In addition to TAN and TBN measurements, a capillary electrophoresis technique is used to evaluate the formate content in the oils. The results suggest that wear properties of used FFV lubricants change significantly with their degree of usage.

A pressure transducer, closely mounted to the fuel rail pressure regulator of a production fuel system, captured transient waveforms in a bench experiment. Signals were processed to detect the reduction of fuel flow caused by injector clogging. Interference among wave patterns and the proximate action of the pressure regulator made quantitative correlation difficult. However, changes in wave amplitudes can be qualitative indicators of injector clogging problems. A modification was made that moved the regulator nearer the fuel pump outlet and deadheaded the rail. With these modifications, sequential transient pulses from a single operating injector showed good correlation between the pressure drop in the fuel rail during injection and the injector static fuel flow rate. To apply this behavior to multi-cylinder engine analysis, a waveform superposition method was developed to extract single injector information during multi-injector operation.