This work describes an updated cold start system for ethanol fuelled engines using an electronic gasoline injector. The new system is a substitute to the conventional cold start system that employs a calibrated hole for gasoline introduction in the intake pipe. The new system is constituted by a gasoline reservoir, electrical fuel pump, fuel injector, fuel filter, and solenoid valve frequency controller. Experiments have been carried out in a production 1.0-liter, four-cylinder, ethanol-fuelled engine, submitted to transient emissions tests after cold start. The results show that the updated system reduces the cold start period by 31% in comparison to the conventional system. Acceleration after cold start was also improved, with gasoline consumption reduction of 67%. Submitting a vehicle powered by the engine equipped with the new cold start system to the cold phase of the US FTP-75 emissions test cycle (first 505 s) in order to evaluate emissions before the catalytic converter, total hydrocarbons and carbon monoxide emissions were reduced by 8.6 and 17.2%, respectively. Aldehydes (formaldehyde and acetaldehyde) and oxides of nitrogen emissions levels did not show significant change when comparing both cold start systems.