The paper describes a procedure of solving an optimal design problem with continuous/discrete design variables. The procedure is applied to a set of design parameters of a conventional fuel injection equipment for a diesel engine. The design parameters concern the design of the cam, high pressure pump, delivery valve, snubber valve, high pressure tube and injector. By the proposed procedure the continuous/discrete optimal design problem is replaced by a finite sequence of auxiliary problems where all design variables are treated as continuous. After solving each auxiliary problem one of the discrete design variables is set equal to the closest available discrete value and eliminated from the set of design variables. This process does not guarantee that an optimal solution to the continuous/integer programming problem is located; however it does produce improved near optimal designs for conventional fuel injection equipment. The proposed procedure is illustrated with a numerical example.