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Increasingly severe noise legislation and customer expectations for improved vehicle refinement continue to require fuel injection equipment manufacturers to reduce the noise generated by injection pumps. The measurement of injection pump noise or, more recently, sound power level has hitherto been carried out in anechoic or semi-anechoic chambers using purpose built quiet drive rigs which have themselves required continual quietening in order to allow accurate measurements to be made. The accuracy and speed of the measurements were improved some years ago with the development of the microcomputer based Lucas-CEL sound power analysis system. However, recent advances in acoustic intensity technology due to the ready availability of low-cost processing power has led to a re-evaluation of the measurement of pump sound power.

The emergence of high speed diesel engines for cars has emphasized the problems of mounting fuel injection pumps onto engines. Some engine manufacturers are using sheet steel pressings or thin cast brackets which allow the pump to vibrate in resonance in the engine firing frequency range. This increases the likelihood of failure of these brackets in service due to metal fatigue. A theoretical analysis of a simple bracket enables the essentials of the problem to be understood and it allows possible design solutions to be evaluated. This theoretical analysis is complemented by experimental evidence from actual brackets.