Editing Diesel engine (section)

=== Unit injectors ===
{{Main|Unit Injector}}
A ''unit injector'' system, also known as "Pumpe-Düse" (''pump-nozzle'' in German) combines the injector and fuel pump into a single component, which is positioned above each cylinder. This eliminates the high-pressure fuel lines and achieves a more consistent injection. Under full load, the injection pressure can reach up to 220&nbsp;MPa.<ref name="Reif Springer Fachmedien Wiesbaden p. 393">{{Cite book |last1=Reif |first1=Konrad |title=Dieselmotor-Management Systeme, Komponenten, Steuerung und Regelung |last2=Springer Fachmedien Wiesbaden |date=2020 |isbn=978-3-658-25072-0 |publication-place=Wiesbaden |page=393 |language=de |oclc=1156847338}}</ref> Unit injectors are operated by a [[Cam (mechanism)|cam]] and the quantity of fuel injected is controlled either mechanically (by a rack or lever) or electronically.

Due to increased performance requirements, unit injectors have been largely replaced by [[common rail]] injection systems.<ref name="Tschöke_2018_295" />