Inspect the fuel supply lines, return lines, filters, and fittings for leaks. Check any flexible sections for cuts, cracks, and abrasions, and make sure they are not rubbing against anything that could cause breakage.
Ensure there is no air in the fuel system. This is a common problem with newer generators that are not run on a regular basis. Closer tolerances within the fuel systems to meet today’s emission requirements make fuel systems more susceptible to air affecting startup.
Diesel fuel is inherently unstable and this instability causes diesel fuels to form sludge and/or insoluble organic particulates. Both asphaltene compounds (sludge) and particulates may contribute to build up in injectors and particulates can clog fuel filters, plus add to the service issues common to diesel engines. Change fuel filters every 200 to 250 hours, depending on environmental conditions and how clean the fuel is. At a minimum, change the filter on an annual basis.
Use a diesel fuel conditioning or cleaning system. Such cleaning and recirculation systems are available from Gregory Poole. These systems typically use well-known, multi-stage separation processes, including coalescence and/or centrifugal principles to clean larger volumes of fuel.
Make sure that mechanical fuel level gauges are functional and accurate.
Make sure fuel level alarms are tested for functionality.
Ensure that you have a reputable and reliable fuel supplier, particularly one that receives their fuel as close to the pipeline as possible.