A method for preventing combustion chamber deposits from causing start-failures in an internal combustion engine comprises operating the engine with a fuel composition that contains a normally liquid fuel and a nitrogen-containing detergent that includes a polyetheramine; a Mannich reaction product of a hydrocarbyl-substituted phenol, an aldehyde and an amine; or a mixture there. The method is effective in preventing start-failures in multi-valve, low friction, spark-ignited engines.