<div class="section abstract"><div class="htmlview paragraph">Engine operation at low temperatures is of considerable interest from the standpoint of exhaust gas emissions and fuel economy. A semi-empirical film model is developed to study the transient cold starting process. Variation of air-to-fuel ratio reaching the cylinder during the starting is estimated. Film-model uses some inputs from the CFD simulation and essentially avoids the multiple cycle CFD simulation.</div><div class="htmlview paragraph">CFD simulation was carried out with unsteady boundary condition obtained from the experiment. The experiments were conducted at different temperatures inside cold chamber. Air-to-fuel ratio variations were recorded after starting which is used for qualitative comparison with the film model. The model is able to capture the qualitative trends observed in the experiment.</div></div>