An injector including a housing having a fluid channel for fluid and a plurality of injector modules fluidly connected to the fluid channel, where each injector module includes a spray cup having a plurality of radial air passages for directing air radially inwardly into the chamber, and a pressure swirl atomizer having a fluid passage for directing fluid in the axial direction and at least one air passage radially outwardly spaced from the fluid passage for directing air in the axial direction, wherein at least one of the injector modules is axially recessed relative to the other injector modules. By axially recessing at least one of the injector modules, a sheltered burning zone may be provided to enhance flame stability when injecting a mixture of air and fuel from the recessed module.