Abstract: Method and apparatus for testing diesel engine governors away from an engine on a test bench, including an electric drive for driving a governor and an associated fuel pump at a variable speed rate which variable speed rate is controlled with an electrical signal generated by a transducer connected to the governor. The signal is applied to the drive through a feed back loop. In this manner variations in the governor output control the drive and consequently the fuel pump delivery rate in a manner that realistically simulates the actual performance of the governor when the governor and fuel pump are mounted on a diesel engine.