An engine-driven welder/generator is controlled by an integrated controller that is coupled to both the engine and to the welder/generator. The controller receives input signals for operational parameters of the engine, and additional signals indicative of electrical output by the welder/generator. Operation of the engine and welder/generator may thus be coordinated. The controller may control speed, timing, fuel injection, and so forth of the engine, and output of the welder/generator, such as by control of input to a field coil.