The invention relates to a fuel injector for injecting an over-enriched fuel and air mixture to the combustion chamber of an internal combustion engine, the fuel injector comprising a hydrocarbon liquid fuel spray nozzle (1), at least one supply (2) of a gaseous carrier, a fuel mixing and evaporation chamber (3) and an injector nozzle (4) to an engine combustion chamber, configured such that, during operation,
liquid fuel is supplied through the spray nozzle to the fuel mixing and evaporation chamber (3), heated, and compressed gaseous carrier is supplied to the fuel mixing and evaporation chamber (3) injector, where both are mixed and evaporated as a result of elevated temperature, and the mixture with low oxygen content formed of evaporated fuel with the hot gaseous carrier reaches the combustion chamber, through the outlet (4), wherein
the gaseous carrier is air or, alternatively, flue gas, at elevated pressure and temperature and having a composition that prevents the initiation of flame combustion, and
the gaseous carrier has oxygen content low enough to prevent the initiation of combustion, even under conditions of elevated pressure and temperature.