To add or remove an FME Engine by editing the Process Monitor configuration:
Open the following file using a text editor:
<FMEServerDir>\Server\processMonitorConfig.txt
Near the end of the file, locate the blocks of text beginning with # Start FME Engine 1
Locate the first line beginning with # CMDFMEEngine and uncomment it (remove #). For example:
CMDFMEEngine_Engine3=...
In the same block, uncomment the line beginning with # WAITFMEEngine. For example:
WAITFMEEngine_Engine3=...
Similarly, if you would like to remove an FME Engine, you can comment out these lines.