Fuel injection#Throttle body injection

{{Short description|Feature of internal combustion engines}}

{{Use dmy dates|date=October 2021}}

{{Use British English|date=April 2022}}

File:PetrolDirectInjectionBMW.JPG

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

All compression-ignition engines (e.g. diesel engines), and many spark-ignition engines (i.e. petrol (gasoline) engines, such as Otto or 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.{{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}} In passenger car petrol engines, fuel injection was introduced in the early 1950s and gradually gained prevalence until it had largely replaced carburetors by the early 1990s.{{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}} The primary difference between carburetion and fuel injection is that fuel injection atomizes the fuel through a small nozzle under high pressure, while carburetion relies on suction created by intake air accelerated through a 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 injection, a variety of direct injection. The term electronic fuel injection refers to any fuel injection system controlled by an engine control unit.

System functions

The fundamental functions of a fuel injection system are described in the following sections. In some systems, a single component performs multiple functions.

= Pressurising fuel =

Fuel injection is operated by spraying pressurised fuel into the engine. Therefore a device to pressurise the fuel is needed, such as a fuel pump.

= Metering fuel =

The system must determine the appropriate amount of fuel to be supplied and control the fuel flow to supply this amount.

Several early mechanical injection systems used relatively sophisticated helix-controlled injection pump(s) that both metered fuel and created injection pressure. Since the 1980s, electronic systems have been used to control the metering of fuel. More recent systems use an electronic engine control unit which meters the fuel and controls the ignition timing and various other engine functions.

= Injecting fuel =

The fuel injector is effectively a spray nozzle that performs the final stage in the delivery of fuel into the engine. The injector is located in the combustion chamber, inlet manifold or{{dash}}less commonly{{dash}}the throttle body.

Fuel injectors which also control the metering are called injection valves, while injectors that perform all three functions are called unit injectors.

Direct injection systems

Direct injection means that the fuel is injected into the main combustion chamber of each cylinder.{{cite web |url= http://www.unep.org/transport/gfei/autotool/approaches/technology/ic_engines.asp |title=IC Engines |work=Global Fuel Economy Initiative |archive-url= https://web.archive.org/web/20121006095155/http://www.unep.org/transport/gfei/autotool/approaches/technology/ic_engines.asp#gasoline |archive-date=2012-10-06 |access-date=2014-05-01}} The air and fuel are mixed only inside the combustion chamber. Therefore, only air is sucked into the engine during the intake stroke. The injection scheme is always intermittent (either sequential or cylinder-individual).

This can be done either with a blast of airRüdiger Teichmann, Günter P. Merker (publisher) or hydraulically, with the latter method being more common in automotive engines. Typically, hydraulic direct injection systems spray fuel into the air inside the cylinder or combustion chamber. Direct injection can be achieved with a conventional helix-controlled injection pump, unit injectors, or a sophisticated common-rail injection system. The last is the most common system in modern automotive engines.

= Direct injection for petrol engines =

{{main|Petrol direct injection}}

During the 20th century, most petrol engines used either a carburettor or indirect fuel injection. Use of direct injection in petrol engines has become increasingly common in the 21st century.

= Common-rail injection systems =

{{Main|Common-rail injection}}

In a common-rail system, fuel from the fuel tank is supplied to a common header (called the accumulator), and then sent through tubing to the injectors, which inject it into the combustion chambers. The accumulator has a high-pressure relief valve to maintain pressure and return the excess fuel to the fuel tank. The fuel is sprayed with the help of a nozzle that is opened and closed with a solenoid-operated needle valve.Helmut Tschöke, Klaus Mollenhauer, Rudolf Maier (ed.): Handbuch Dieselmotoren, 8th edition, Springer, Wiesbaden 2018, {{ISBN|978-3-658-07696-2}}, p. 289 Third-generation common-rail diesels use piezoelectric injectors for increased precision, with fuel pressures up to {{convert|300|MPa|psi|abbr=on|lk=on|disp=or}}.Helmut Tschöke, Klaus Mollenhauer, Rudolf Maier (ed.): Handbuch Dieselmotoren, 8th edition, Springer, Wiesbaden 2018, {{ISBN|978-3-658-07696-2}}, p. 1000

The types of common-rail systems include air-guided injectionRichard van Basshuysen (ed.): Ottomotor mit Direkteinspritzung und Direkteinblasung: Ottokraftstoffe, Erdgas, Methan, Wasserstoff, 4th edition, Springer, Wiesbaden 2017, {{ISBN|978-3-658-12215-7}}, p. 62 and spray-guided injection.

= Unit injector systems =

{{main|Unit injector}}

Used by diesel engines, these systems include:

  • Pumpe-DüseHelmut Tschöke, Klaus Mollenhauer, Rudolf Maier (ed.): Handbuch Dieselmotoren, 8th edition, Springer, Wiesbaden 2018, {{ISBN|978-3-658-07696-2}}, p. 295
  • Pump-rail-nozzle system

= Helix-controlled pump systems =

This injection method was previously used in many diesel engines. Types of systems include:

  • Lanova direct injectionHelmut Hütten: Motoren. Technik, Praxis, Geschichte. Motorbuchverlag, Stuttgart 1982, {{ISBN|3-87943-326-7}}
  • Afterchamber injection{{cite book |editor-last1=von Fersen |editor-first1=Olaf |title=Ein Jahrhundert Automobiltechnik: Nutzfahrzeuge |date=1987 |publisher=Springer |location=Berlin, Heidelberg |isbn=978-3-662-01120-1 |page=131 |language=de}}
  • G-System (sphere combustion chamber)Hellmut Droscha (ed.): Leistung und Weg – Zur Geschichte des MAN-Nutzfahrzeugbaus, Springer, Berlin/Heidelberg 1991, {{ISBN|978-3-642-93490-2}}. p. 429
  • Gardner system (hemisphere combustion chamber)
  • Saurer system (torus combustion chamber)
  • Flat piston (combustion chamber between piston and head)

= Air-blast injection systems =

{{main|Air-blast injection}}

= Other systems =

The M-System, used in some diesel engines from the 1960s to the 1980s, sprayed the fuel onto the walls of the combustion chamber,Hellmut Droscha (ed.): Leistung und Weg – Zur Geschichte des MAN-Nutzfahrzeugbaus, Springer, Berlin/Heidelberg 1991, {{ISBN|978-3-642-93490-2}}. p. 433 as opposed to most other direct-injection systems which spray the fuel into the middle of the chamber.

Indirect injection systems

= Manifold injection =

{{main|Manifold injection}}

Manifold injection systems are common in petrol-fuelled engines such as the Otto engine and the Wankel engine. In a manifold injection system, air and fuel are mixed outside the combustion chamber so that a mixture of air and fuel is sucked into the engine. The main types of manifold injections systems are multi-point injection and single-point injection.

These systems use either a continuous injection or an intermittent injection design. In a continuous injection system, fuel flows at all times from the fuel injectors, but at a variable flow rate. The most common automotive continuous injection system is the Bosch K-Jetronic system, introduced in 1974 and used until the mid-1990s by various car manufacturers. Intermittent injection systems can be sequential, in which injection is timed to coincide with each cylinder's intake stroke; batched, in which fuel is injected to the cylinders in groups, without precise synchronization to any particular cylinder's intake stroke; simultaneous, in which fuel is injected at the same time to all the cylinders; or cylinder-individual, in which the engine control unit can adjust the injection for each cylinder individually.Konrad Reif (ed.): Ottomotor-Management, 4th edition, Springer, Wiesbaden 2014, {{ISBN|978-3-8348-1416-6}}, p. 107

== Multi-point injection ==

File:Marvel Fuel Injection System Cross Section.png

Multi-point injection (also called 'port injection') injects fuel into the intake ports just upstream of each cylinder's intake valve, rather than at a central point within an intake manifold.{{cite web |title=Multi Point Fuel Injection or MPFI System- Working, advantages |url=https://www.enggstudy.com/multi-point-fuel-injection-system-mpfi/#Disadvantages_of_MPFI_system |access-date=26 December 2022 |date=25 November 2019}} Typically, multi-point injected systems use multiple fuel injectors, but some systems, such as GM's central port injection system, use tubes with poppet valves fed by a central injector instead of multiple injectors.1997 Chevrolet Truck Service Manual, page 6A-24, drawing, item (3) Central Sequential Muliport injector.

== Single-point injection ==

{{Anchor|TBI|EGI|CFI|SPI|Throttle body injection}}

Single-point injection (also called 'throttle-body injection'){{cite web |title=How Fuel Injection Systems Work |url=https://auto.howstuffworks.com/fuel-injection.htm |website=HowStuffWorks |access-date=26 December 2022 |language=en-us |date=4 January 2001}} uses one injector in a throttle body mounted similarly to a carburettor on an intake manifold. As in a carburetted induction system, the fuel is mixed with the air before entering the intake manifold.Kurt Lohner, Herbert Müller (auth): Gemischbildung und Verbrennung im Ottomotor, in Hans List (ed.): Die Verbrennungskraftmaschine, Band 6, Springer, Wien 1967, {{ISBN|978-3-7091-8180-5}}, p. 64 Single-point injection was a relatively low-cost way for automakers to reduce exhaust emissions to comply with tightening regulations while providing better "driveability" (easy starting, smooth running, no engine stuttering) than could be obtained with a carburettor. Many of the carburettor's supporting components—such as the air filter, intake manifold, and fuel line routing—could be used with few or no changes. This postponed the redesign and tooling costs of these components. Single-point injection was used extensively on American-made passenger cars and light trucks during 1980–1995, and in some European cars in the early and mid-1990s.

In the US, the G10 engine in the 2000 Chevrolet Metro became the last engine available on an American-sold vehicle to use throttle body injection.

= Diesel engines =

In indirect-injected diesel engines (as well as Akroyd engines), there are two combustion chambers: the main combustion chamber, and a pre-chamber (also called an ante-chamber){{cite book |first=Ellison |last=Hawks |title=How it works and how it's done |publisher=Odhams Press |location=London |year=1939 |page=75}} that is connected to the main one. The fuel is injected only into the pre-chamber (where it begins to combust), and not directly into the main combustion chamber. Therefore, this principle is called indirect injection. There exist several slightly different indirect injection systems that have similar characteristics.Olaf von Fersen (ed.): Ein Jahrhundert Automobiltechnik. Personenwagen, VDI-Verlag, Düsseldorf 1986, {{ISBN|978-3-642-95773-4}}. p. 273

Types of indirect injection used by diesel engines include:

= Hot-bulb injection =

{{main|Hot-bulb engine}}

History

= 1870s–1930s: early systems =

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| image1 = Lufteinblasflaschen.jpg

| caption1 = Air-blast injection system for an 1898 diesel engine

| image2 = Moteur de l Antoinette VII Musee du Bourget P1010360.JPG

| caption2 = Mechanical port injection system on a 1906 Antoinette 8V engine

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In 1872, George Bailey Brayton obtained a patent on an internal combustion engine that used a pneumatic fuel injection system, also invented by Brayton: air-blast injection.Sass{{refpage|p=413}} In 1894, Rudolf Diesel copied Brayton's air-blast injection system for the diesel engine, but also improved it.Sass{{refpage|p=414}} He increased the air blast pressure from {{cvt|4-5|kp/cm2|kPa psi|order=out}} to {{cvt|65|kp/cm2|kPa psi|order=out}}.Sass{{refpage|p=415}} In the meantime, the first manifold injection system was designed by Johannes Spiel in 1884, while working at Hallesche Maschinenfabrik in Germany.Richard van Basshuysen (ed.): Ottomotor mit Direkteinspritzung und Direkteinblasung: Ottokraftstoffe, Erdgas, Methan, Wasserstoff, 4th edition, Springer, Wiesbaden 2017, {{ISBN|978-3-658-12215-7}}, p. 6

In 1891, the British Herbert-Akroyd oil engine became the first engine to use a pressurised fuel injection system.{{cite book | last = Ransome-Wallis | first = Patrick | title = Illustrated Encyclopedia of World Railway Locomotives | publisher = Courier Dover Publications | year = 2001 | page = 27 | isbn = 0-486-41247-4}}{{Cite book|title=A Biographical Dictionary of People in Engineering: From Earliest Records to 2000|last=Hall|first=Carl W.|publisher=Purdue University Press|year=2008|edition=1st|via=Credo Reference}} This design, called a hot-bulb engine used a 'jerk pump' to dispense fuel oil at high pressure to an injector. Another development in early diesel engines was the pre-combustion chamber, which was invented in 1919 by Prosper l'Orange{{cite book | last=Mau | first=Günter | title=Handbuch Dieselmotoren im Kraftwerks- und Schiffsbetrieb | publisher=Vieweg+Teubner Verlag | year=1984 | isbn=978-3-322-90621-2 | language=de | page=11}} to avoid the drawbacks of air-blast injection systems. The pre-combustion chamber made it feasible to produce engines in size suitable for automobiles and MAN Truck & Bus presented the first direct-injected diesel engine for trucks in 1924.von Fersen (ed.), p. 130 Higher pressure diesel injection pumps were introduced by Bosch in 1927.

In 1898, German company Deutz AG started producing four-stroke petrol stationary engines{{cite journal |last1=Cummins, Jr. |first1=C. Lyle |date=1976 |title=Early IC and Automotive Engines |url=https://www.jstor.org/stable/44648442 |journal=SAE Transactions |volume=85 |issue=3 |pages=1966 |doi= |jstor=44648442 |access-date=2024-02-07}} with manifold injection.{{citation needed|date=December 2022}} The 1906 Antoinette 8V aircraft engine (the world's first V8 engine) was another early four-stroke engine that used manifold injection. The first petrol engine with direct-injection was a two-stroke aircraft engine designed by Otto Mader in 1916.Richard van Basshuysen (ed.): Ottomotor mit Direkteinspritzung und Direkteinblasung: Ottokraftstoffe, Erdgas, Methan, Wasserstoff, 4th edition, Springer, Wiesbaden 2017, {{ISBN|978-3-658-12215-7}}, p. 7 Another early spark-ignition engine to use direct-injection was the 1925 Hesselman engine, designed by Swedish engineer Jonas Hesselman.{{cite book |title=Scania fordonshistoria 1891-1991 |first=Björn-Eric |last=Lindh |year=1992 |publisher=Streiffert |language=sv |isbn=978-91-7886-074-6}}{{cite book |title=Volvo – Lastbilarna igår och idag |first=Christer |last=Olsson |year=1990 |publisher=Förlagshuset Norden |language=sv |isbn=978-91-86442-76-7}} This engine could run on a variety of fuels (such as oil, kerosene, petrol or diesel oil)Richard van Basshuysen (ed.): Ottomotor mit Direkteinspritzung und Direkteinblasung: Ottokraftstoffe, Erdgas, Methan, Wasserstoff, 4th edition, Springer, Wiesbaden 2017, {{ISBN|978-3-658-12215-7}}, pp. 17–18 and used a stratified charge principle whereby fuel is injected towards the end of the compression stroke, then ignited with a spark plug.

The Cummins Model H diesel truck engine was introduced in America in 1933.{{cite web |title=1933 Kenworth Cummins Diesel – The First American Production Diesel Truck And With The First Vertical Exhaust Stack |url=https://www.curbsideclassic.com/automotive-histories/vintage-trucks-1933-kenworth-cummins-diesel-the-first-american-production-diesel-truck-and-the-first-vertical-exhaust-stack/ |website=Curbside Classic |access-date=24 December 2022 |date=7 December 2021}} In 1936, the Mercedes-Benz OM 138 diesel engine (using a precombustion chamber) became one of the first fuel-injected engines used in a mass-production passenger car.Olaf von Fersen (ed.): Ein Jahrhundert Automobiltechnik. Personenwagen, VDI-Verlag, Düsseldorf 1986, {{ISBN|978-3-642-95773-4}}. p. 274

= 1940s–1950s: WWII aircraft and early direct-injection petrol engines =

During World War II, several petrol engines for aircraft used direct-injection systems, such as the European Junkers Jumo 210, Daimler-Benz DB 601, BMW 801, and the Shvetsov ASh-82FN (M-82FN). The German direct-injection systems were based on diesel injection systems used by Bosch, Deckel, Junkers and l'Orange.Richard van Basshuysen (ed.): Ottomotor mit Direkteinspritzung und Direkteinblasung: Ottokraftstoffe, Erdgas, Methan, Wasserstoff, 4th edition, Springer, Wiesbaden 2017, {{ISBN|978-3-658-12215-7}}, p. 10 By around 1943, the Rolls-Royce Merlin and Wright R-3350 had switched from traditional carburettors to fuel-injection (called "pressure carburettors" at the time), however these engines used throttle body manifold injection, rather than the direct-injection systems of the German engines. From 1940, the Mitsubishi Kinsei 60 series engine used a direct-injection system, along with the related Mitsubishi Kasei engine from 1941. In 1943, a low-pressure fuel injection system was added to the Nakajima Homare Model 23 radial engine.{{cite journal |url= https://saemobilus.sae.org/content/881610/ |title=Engine Fuels and Lubrication Systems at Nakajima Aircraft Co. from 1936–1945 [sic] |first1=Ryoichi |last1=Nakagawa |first2=Sotaro |last2=Mizutani |year=1988 |doi=10.4271/881610 |journal=Mobilus |series=SAE Technical Paper Series |volume=1 |publisher=Society of Automobile Engineers |location=US |issn=0148-7191 |eissn=2688-3627 |url-access=subscription}}

The first mass-produced petrol direct-injection system was developed by Bosch and initially used in small automotive two-stroke petrol engines. Introduced in the 1950 Goliath GP700 small saloon, it was also added to the Gutbrod Superior engine in 1952. This mechanically-controlled system was essentially a specially lubricated high-pressure diesel direct-injection pump of the type that is governed by the vacuum behind an intake throttle valve.Richard van Basshuysen (ed.): Ottomotor mit Direkteinspritzung und Direkteinblasung: Ottokraftstoffe, Erdgas, Methan, Wasserstoff, 4th edition, Springer, Wiesbaden 2017, {{ISBN|978-3-658-12215-7}}, p. 19 A Bosch mechanical direct-injection system was also used in the straight-eight used in the 1954 Mercedes-Benz W196 Formula One racing car. The first four-stroke direct-injection petrol engine for a passenger car was released the following year, in the Mercedes-Benz 300SL sports car.Richard van Basshuysen (ed.): Ottomotor mit Direkteinspritzung und Direkteinblasung: Ottokraftstoffe, Erdgas, Methan, Wasserstoff, 4th edition, Springer, Wiesbaden 2017, {{ISBN|978-3-658-12215-7}}, p. 20 However the engine suffered lubrication problems due to petrol diluting the engine oil,{{cite web |title=Mercedes-Benz 300 SL |url=https://jalopnik.com/mercedes-benz-300-sl-309046 |website=www.jalopnik.com |access-date=26 December 2022 |language=en |date=10 October 2007}}{{cite magazine |title=Driving the Awesome Mercedes 300 SL 'Gullwing'{{dash}}slide 8/22 |url=https://www.wired.com/2011/01/driving-the-awesome-mercedes-300-sl-gullwing/ |magazine=Wired |access-date=26 December 2022 |last1=Smith |first1=Sam }} and subsequent Mercedes-Benz engines switched to a manifold injection design. Likewise, most petrol injection systems prior to the 2000s used the less-expensive manifold injection design.

= 1950s–1970s: manifold injection for petrol engines =

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| caption1 = 1950s Rochester Ramjet mechanical port injection system (on a Chevrolet 283 engine)

| image2 = BMW Engine M88 from a M1.JPG

| caption2 =1970s Kugelfischer mechanical port injection system (on a BMW M88 engine)

| image3 = K-Jet MT1.jpg

| caption3 = Components of a 1970s K-Jetronic electronic port injection system

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Throughout the 1950s, several manufacturers introduced their manifold injection systems for petrol engines. Lucas Industries had begun developing a fuel injection system in 1941 and by 1956 it was used in the Jaguar racing cars.{{cite web |url= http://www.lucasinjection.com/HISTORY.htm |title=A short history of Lucas injection |publisher=lucasinjection.com |access-date=2015-05-01}} At the 1957 24 Hours of Le Mans, the 1st to 4th placed cars were Jaguar D-Type entries using a Lucas fuel injection system.{{cite web |title=Lucas Le Mans 1957 |url=https://www.lucasinjection.com/lucaslemas1957.jpg |website=www.lucasinjection.com |access-date=25 December 2022}} Also in 1957, General Motors introduced the Rochester Ramjet option, consisting of a fuel injection system for the V8 engine in the Chevrolet Corvette. During the 1960s, fuel injection systems were also produced by Hilborn,{{cite journal |last=Walton |first=Harry |title=How Good is Fuel Injection? |journal=Popular Science |date=March 1957 |volume=170 |issue=3 |pages=88–93 |url= https://books.google.com/books?id=byEDAAAAMBAJ&pg=PA88 |access-date=2015-05-01}} SPICA{{Cite web |title=Spica Fuel Injection |url=https://www.hemmings.com/stories/article/spica-fuel-injection |access-date=2023-10-30 |website=www.hemmings.com}} and Kugelfischer.

Up until this time, the fuel injection systems had used a mechanical control system. In 1957, the American Bendix Electrojector system was introduced, which used analogue electronics for the control system. The Electrojector was intended to be available for the Rambler Rebel mid-size car, however reliability problems meant that the fuel injection option was not offered.{{cite news |url= http://select.nytimes.com/gst/abstract.html?res=F60C16FD355A137A93C6AB1788D85F438585F9 |last=Ingraham |first=Joseph C. |title=Automobiles: Races; Everybody Manages to Win Something at the Daytona Beach Contests |newspaper=The New York Times |date=1957-03-24 |page=153 |access-date=2015-05-01}}{{cite journal |journal=Consumer Reports |year=1957 |volume=22 |title=1957 cars |page=154}}{{cite book |last=Aird |first=Forbes |title=Bosch fuel injection systems |publisher=HP Trade |year=2001 |page=29 |isbn=978-1-55788-365-0}}{{cite web |url= http://www.petersen.org/default.cfm?docid=1034 |first=Leslie |last=Kendall |title=American Musclecars: Power to the People |publisher=Petersen Automotive Museum |archive-url= https://web.archive.org/web/20111027060937/http://www.petersen.org/default.cfm?docid=1034 |archive-date=2011-10-27 |access-date=2022-03-13}}{{cite web |url= http://auto.howstuffworks.com/1957-1960-rambler-rebel2.htm |title=Rambler Measures Up |website=How Stuff Works |date=2007-08-22 |archive-url= https://web.archive.org/web/20200729153245/http://auto.howstuffworks.com/1957-1960-rambler-rebel2.htm |archive-date=2020-07-29 |access-date=2022-03-13}} In 1958, the Chrysler 300D, DeSoto Adventurer, Dodge D-500 and Plymouth Fury offered the Electrojector system, becoming the first cars known to use an electronic fuel injection (EFI) system.{{cite web |title=1958 Chrysler-DeSoto Electrojector - World's First Electronic Fuel Injection|last1=Mattar|first1=George|url= https://www.allpar.com/cars/desoto/electrojector.html |website=Allpar|access-date=2018-11-08}}

The Electrojector patents were subsequently sold to Bosch, who developed the Electrojector into the Bosch D-Jetronic.{{cite web |title=D-Jetronic History and Fundamentals |url=http://members.rennlist.com/pbanders/djetfund.htm |website=www.rennlist.com |access-date=26 December 2022 |archive-url=https://web.archive.org/web/20100809110201/http://members.rennlist.com/pbanders/djetfund.htm |archive-date=9 August 2010 |url-status=live}} The D-Jetronic was produced from 1967-1976 and first used on the VW 1600TL/E. The system was a speed/density system, using engine speed and intake manifold air density to calculate the amount of fuel to be injected. In 1974, Bosch introduced the K-Jetronic system, which used a continuous flow of fuel from the injectors (rather than the pulsed flow of the D-Jetronic system). K-Jetronic was a mechanical injection system, using a plunger actuated by the intake manifold pressure which then controlled the fuel flow to the injectors.Olaf von Fersen (ed.): Ein Jahrhundert Automobiltechnik. Personenwagen, VDI-Verlag, Düsseldorf 1986, {{ISBN|978-3-642-95773-4}}. p. 256

Also in 1974, Bosch introduced the L-Jetronic system, a pulsed flow system which used an air flow meter to calculate the amount of fuel required. L-Jetronic was widely adopted on European cars during the 1970s and 1980s. As a system that uses electronically-controlled fuel injectors which open and close to control the amount of fuel entering the engine, the L-Jetronic system uses the same basic principles as modern electronic fuel injection (EFI) systems.

= 1980s–present: digital electronics and common-rail injection=

Prior to 1979, the electronics in fuel injection systems used analogue electronics for the control system. The Bosch Motronic multi-point fuel injection system (also amongst the first systems where the ignition system is controlled by the same device as the fuel injection system) was the first mass-produced system to use digital electronics. The Ford EEC-III single-point fuel injection system, introduced in 1980, was another early digital fuel injection system.{{cite web |url= http://www.motorola.com/staticfiles/Consumers/Corporate/US-EN/_Documents/Motorola_History_Timeline.pdf |title=A Timeline Overview of Motorola History 1928-2009 |publisher=Motorola |archive-url= https://web.archive.org/web/20110620224820/http://www.motorola.com/staticfiles/Consumers/Corporate/US-EN/_Documents/Motorola_History_Timeline.pdf |archive-date=2011-06-20 |access-date=2014-01-20}}Olaf von Fersen (ed.): Ein Jahrhundert Automobiltechnik. Personenwagen, VDI-Verlag, Düsseldorf 1986, {{ISBN|978-3-642-95773-4}}. p. 262 These and other electronic manifold injection systems (using either port injection or throttle-body injection) became more widespread through the 1980s, and by the early 1990s they had replaced carburettors in most new petrol-engined cars sold in developed countries.

The aforementioned injection systems for petrol passenger car engines{{dash}}except for the 1954–1959 Mercedes-Benz 300 SL{{dash}}all used manifold injection (i.e. the injectors located at the intake ports or throttle body, instead of inside the combustion chamber). This began to change when the first mass-produced petrol direct injection system for passenger cars was a common rail system introduced in the 1997 Mitsubishi 6G74 V6 engine.Richard van Basshuysen (ed.): Ottomotor mit Direkteinspritzung und Direkteinblasung: Ottokraftstoffe, Erdgas, Methan, Wasserstoff, 4th edition, Springer, Wiesbaden 2017, {{ISBN|978-3-658-12215-7}}, p. 138{{cite web |title=Mitsubishi Motors Adds World First V6 3.5-liter GDI Engine to Ultra-efficiency GDI Series |url= http://media.mitsubishi-motors.com/pressrelease/e/corporate/detail215.html |website=mitsubishi-motors.com |archive-url= https://web.archive.org/web/20091001184522/http://media.mitsubishi-motors.com/pressrelease/e/corporate/detail215.html |archive-date=1 October 2009 }} [https://www.3si.org/threads/direct-gas-injection-any-one-tried.477519/ Alt URL] The first common-rail system for a passenger car diesel engine was the Fiat Multijet{{Broken anchor|date=2024-07-03|bot=User:Cewbot/log/20201008/configuration|target_link=Fiat_JTD_engine#1.9|reason= The anchor (1.9) has been deleted.}} straight-four engine,Günter P. Merker, Rüdiger Teichmann (ed.): Grundlagen Verbrennungsmotoren – Funktionsweise · Simulation · Messtechnik, 7th edition, Springer, Wiesbaden 2014, {{ISBN|978-3-658-03194-7}}, p. 179 introduced in the 1999 Alfa Romeo 156 1.9 JTD model. Since the 2010s, many petrol engines have switched to direct-injection (sometimes in combination with separate manifold injectors for each cylinder). Similarly, many modern diesel engines use a common-rail design.

Stratified charge injection was used in several petrol engines in the early 2000s, such as the Volkswagen 1.4 FSI engine introduced in 2000. However, the stratified charge systems were largely no longer in use by the late 2010s, due to increased exhaust emissions of NOx gasses and particulates, along with the increased cost and complexity of the systems.

See also

References

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Category:Engine components

Category:Fuel injection systems