Editing Fuel injection (section)

{{Short description|Feature of internal combustion engines}}
{{Use dmy dates|date=October 2021}}
{{Use British English|date=April 2022}}

[[File:PetrolDirectInjectionBMW.JPG|thumb|A cutaway model of a petrol direct-injected engine]]

'''Fuel injection''' is the introduction of [[fuel]] in an [[internal combustion engine]], most commonly [[automotive engine]]s, by the means of a fuel injector. This article focuses on fuel injection in [[Reciprocating engine|reciprocating piston]] and [[Wankel engine|Wankel rotary]] engines.

All compression-ignition engines (e.g. [[diesel engine]]s), and many spark-ignition engines (i.e. [[petrol engines|petrol (gasoline) engines]], such as [[Otto engine|Otto]] or [[Wankel engine|Wankel]]), use fuel injection of one kind or another. Mass-produced diesel engines for passenger cars (such as the [[Mercedes-Benz OM 138]]) became available in the late 1930s and early 1940s, being the first fuel-injected engines for passenger car use.<ref>{{cite book |last1=Kremser |first1=H. |title=Der Aufbau schnellaufender Verbrennungskraftmaschinen für Kraftfahrzeuge und Triebwagen |page=125 |volume=11 |date=1942 |publisher=Springer |location=Vienna |isbn=978-3-7091-5016-0 |language=de}}</ref> In passenger car petrol engines, fuel injection was introduced in the early 1950s and gradually gained prevalence until it had largely replaced [[carburetor]]s by the early 1990s.<ref>{{cite web |last1=Welshans |first1=Terry |title=A Brief History of Aircraft Carburetors and Fuel Systems |url= http://www.enginehistory.org/Accessories/HxFuelSys/FuelSysHx01.shtml |website=enginehistory.org |publisher=Aircraft Engine Historical Society |location=US |access-date=2016-06-28 |date=August 2013}}</ref> The primary difference between carburetion and fuel injection is that fuel injection [[atomizer nozzle|atomizes]] the fuel through a small nozzle under high pressure, while carburetion relies on [[suction]] created by intake air accelerated through a [[Venturi effect|Venturi tube]] to draw fuel into the airstream.

The term ''fuel injection'' is vague and comprises various distinct systems with fundamentally different functional principles. The only thing all fuel injection systems have in common is the absence of [[carburetion]]. There are two main functional principles of mixture formation systems for internal combustion engines: ''internal'' and ''external''. A fuel injection system that uses external mixture formation is called a [[manifold injection]] system. There exist two types of manifold injection systems: ''multi-point'' (or ''port'') and ''single-point'' (or ''[[throttle body]]'') injection. Internal mixture formation systems can be separated into several different varieties of ''direct'' and ''indirect'' injection, the most common being the [[Common rail|''common-rail'' injection]], a variety of direct injection. The term ''electronic fuel injection'' refers to any fuel injection system controlled by an [[engine control unit]].