(57) A fuel metering system for an internal combustion engine uses a digital computer to calculate the desired fuel flow to maintain an air/fuel ratio required under the engine operating conditions existing at the time. This desired fuel flow is obtained from a basic fuel metering system and, under equilibrium engine operating conditions, is the actual fuel flow demand of the engine. Under transient engine operating conditions, the invention provides compensation of the basic fuel metering system calculations to take into account the effects of the transfer of fuel from the liquid state on the wall surfaces of the engine's intake passages to the gas or vapor state in the inducted air fuel mixture and also takes into account transfers of fuel from the inducted air/fuel mixture onto the intake passage surfaces as a liquid deposit.