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This paper reviews the practice of using mixture enrichment to address cold starting and warm-up difficulties. Excess fuel requirements for gasoline and methanol-based fuels such as M85 are discussed, and the environmental costs inherent in this approach are assessed. A rationale is presented for adopting cold starting approaches which avoid the need for excessively rich mixtures. A synergistic combination of plasma jet ignition and prompt exhaust gas recirculation is proposed as a means of realizing this goal and recent experimental results for both elements of the system are described.

This paper summarizes the results of a survey and analysis of cold starting data for spark ignition engines utilizing high methanol blends. All available published information, as well as additional data supplied by contributing agencies was considered. The report includes graphical comparisons of test results and a detailed discussion of the various factors which influence cold starting. Recommendations are made for further work needed to improve cold starting.

This paper summarizes the results of a survey and analysis of cold starting data for spark ignition engines utilizing neat methanol. All available published information, as well as additional data supplied by contributing agencies was considered. The report includes graphical comparisons of test results and a detailed discussion of the various factors which influence cold starting. Recommendations are made for further work needed to improve cold starting.

This paper presents an analytical study of intake manifold fuel film transient behaviour. It is shown that the overall film response after a step change in airflow consists of two disturbances. A transverse wave imposes the new shear stress distribution, starting at the film surface and moving down through the film towards the wall normal to the film flow direction. A longitudinal wave advances down the length of the manifold parallel to film flow direction. The transverse wave is much faster than the longitudinal wave, is independent of air and fuel velocities and penetrates the film at a rate dependent only upon kinematic viscosity. The longitudinal wave depends upon new and old steady state conditions as well as fluid properties, and usually dominates the overall film response because of its much slower reaction. The model is used to examine transient engine behaviour, particularly under cold conditions.