Ducati Diavel Workshop Manual page 271

Introduction to the engine control system
The drawing shows the layout for the fuel system circuit. The pipes (4) with grey arrows are the delivery lines of the
electric pump, which carry fuel to the injectors. The pipe (3) with black arrows is the fuel return line. The fuel return line
is connected to the pressure regulator, which is submerged in the tank with the pump and the filter. As a result, the
pressure in the fuel delivery and return lines is the same.
1 Fuel electric pump
2 Fuel filter
3 Return line
4 Delivery line
5 Injectors
The image shows the pipes in the fuel supply circuit.
Checking regulated fuel pressure and fuel flow rate
The pressure regulator, submerged in the fuel tank together with the pump and the filter, maintains the same pressure of
3 bar in both the delivery and the return lines. This pressure may be checked by connecting a pressure gauge to a T union
connected to one of the two connectors on the tank. To measure this value, the engine must be running or the pump
activated from the DDS. The T union means that the both injectors and the fuel gauge receive fuel pressure
simultaneously. The regulated fuel pressure is 3 bar.
To measure the fuel flow rate, disconnect the return line from the tank, place the free end of the line in a graduated
container and start the engine or activate the electric pump from the DDS.
Warning
When checking fuel pressure and flow rate by activating the pump from the DDS, check that the battery is fully charged
to ensure correct operation of the pump itself.