A fuel high-pressure connection and a fuel return connection (16) are also provided.

In order to create a fuel injection device (1) that has a simple design and can be produced cost-effectively, the return flow connection (40) and the electric connection (33) are integrated in a common connecting member.

The valve has a feed connection (5), a return connection (16) and, between said connections, a connection (10, 11) for both sides of a servo motor (14).

A first return flow connection (71) is provided for discharging the control quantity of the control space of the nozzle needle, and a second return flow connection (72) is provided for discharging the control quantity of the pressure boosting device.

A heat exchanger has a multi-lumen tubing having one end connected to a supply fitting and another end connected to a return fitting.

A fluid return fitting is in fluid communication with the heating fluid conduit and with the heated fluid supply in use.