M40 and Jetronic: Difference between pages

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=Upgrades=
'''Jetronic''' is a trade name of a  manifold injection  technology for automotive  petrol engine s, developed and marketed by  Robert Bosch GmbH  from the 1960s onwards. Bosch licensed the concept to many  automotive industry|automobile manufacturers . There are several variations of the technology offering technological development and refinement.


==Intake==
== D-Jetronic (1967–1979)==
For most Stage 0.5-1.5 M40, an upgraded drop-in filter is usually perfectly fine and offers a similar power gain to a full intake system. At higher power levels, upgrading the intake system will be more worthwhile.
Analogue fuel injection, 'D' is from {{lang-de|"Druck"}} meaning pressure. Inlet  manifold vacuum  is measured using a pressure sensor located in, or connected to the  intake manifold , in order to calculate the duration of fuel injection pulses. Originally, this system was called Jetronic, but the name D-Jetronic was later created as a  retronym  to distinguish it from subsequent Jetronic iterations.


==Exhaust==
D-Jetronic was essentially a further refinement of the  Bendix Electrojector|Electrojector  fuel delivery system developed by the  Bendix Corporation  in the late 1950s. Rather than choosing to eradicate the various reliability issues with the Electrojector system, Bendix instead licensed the design to Bosch. With the role of the Bendix system being largely forgotten D-Jetronic became known as the first widely successful precursor of modern electronic common rail systems; it had constant pressure fuel delivery to the injectors and pulsed injections, albeit grouped (2 groups of injectors pulsed together) rather than sequential (individual injector pulses) as on later systems.
The stock exhaust manifold is relatively good for OE. Upgrading this component is still a worthwhile investment, and can reduce weight, temperatures, and increase overall engine efficiency.


A cat-back exhaust offers the least gains in comparison to intake and exhaust manifold. 57-76 mm (2.25-3 inch) diameters are ideal, though there is minimal difference beyond 65 mm (2.5 in) diameter at lower modification levels. Please consider the weight difference to power gain and decide what works best for you.
As in the Electrojector system, D-Jetronic used  Analogue electronics|analogue  circuitry, with no  microprocessor  nor  Logic gate|digital logic , the Electronic control unit|ECU  used about 25  Transistor|transistors  to perform all of the processing. Two important factors that led to the ultimate failure of the Electrojector system: the use of paper-wrapped capacitors unsuited to heat-cycling and amplitude modulation (AM radio) signals to control the injectors were superseded. The still present lack of processing power and the unavailability of solid-state sensors meant that the vacuum sensor was a rather expensive precision instrument, rather like a  barometer , with brass bellows inside to measure the manifold pressure.


==Fuel==
Although conceptually similar to most later systems with individual electrically controlled injectors per cylinder, and Pulse-width modulation|pulse-width modulated  fuel delivery, the fuel pressure was not modulated by manifold pressure, and the injectors were fired only once per 2 revolutions on the engine (with half of the injectors being fired each revolution).
===Injectors===
The stock M42 fuel injectors are 18.25 lb/hr @ 3.0 bar and support 125 WHp safely, or 145 WHp maximum.
===Fuel Pump===
The stock M42 fuel pump flows 130 liters per hour. This tends to handle upwards of 220-250 WHp.


==Head==
The system was last used (with a  Lucas Industries|Lucas  designed timing mechanism and Lucas labels super-imposed on some components) on the Jaguar V12 engine ( Jaguar XJ|XJ12  and  Jaguar XJS|XJ-S ) from 1975 until 1979.


===Camshaft===
=={{anchor|K}}K-Jetronic (1973–1994)==
Read the [[camshaft]] page for more information.
Mechanical fuel injection, 'K' stands for {{lang-de|"Kontinuierlich"}}, meaning ''continuous''. Commonly called 'Continuous Injection System (CIS) in the USA. K-Jetronic is different from pulsed injection systems in that the fuel flows continuously from all injectors, while the  Fuel pump (engine)|fuel pump  pressurises the fuel up to approximately 5  bar (unit)|bar  (73.5  pounds per square inch|psi ). The volume of air taken in by the engine is measured to determine the amount of fuel to inject. This system has no  oxygen sensor|lambda  loop or lambda control. K-Jetronic debuted in the 1973.5  Porsche 911 T in January 1973, and was later installed into a number of  Porsche ,  Volkswagen ,  Audi ,  BMW ,  Mercedes-Benz ,  List of Rolls-Royce motor cars|Rolls-Royce ,  Bentley ,  Lotus Cars|Lotus ,  Ferrari ,  Peugeot ,  Nissan ,  Renault ,  Volvo Cars|Volvo ,  Saab Automobile|Saab ,  TVR  and  Ford  automobiles. The final car to use K-Jetronic was the 1994 Porsche 911 Turbo 3.6.


===Valvetrain===
Fuel is pumped from the tank to a large control valve called a ''fuel distributor'', which divides the single fuel supply line from the tank into smaller lines, one for each injector. The fuel distributor is mounted atop a control vane through which all intake air must pass, and the system works by varying fuel volume supplied to the injectors based on the angle of a  Mass flow sensor#Moving vane meter|moving vane  in the  air flow meter , which in turn is determined by the volume of air passing the vane, and by the control pressure. The control pressure is regulated with a mechanical device called the control pressure regulator (CPR) or the warm-up regulator (WUR). Depending on the model, the CPR may be used to compensate for altitude, full load, and/or a cold engine. The injectors are simple spring-loaded  check valve s with nozzles; once fuel system pressure becomes high enough to overcome the counterspring, the injectors begin spraying.
+1 mm oversized valves are a worthwhile upgrade. If you plan to rev high, the most important upgrades are valve springs and rockers.


==Block==
=={{anchor|KL}}K-Jetronic (Lambda)==
First introduced in the  Volvo 240|Volvo 265  in 1976 and later used in the  DeLorean Motor Company|DeLorean  in 1981. A variant of  Jetronic#K-Jetronic .281973.E2.80.931994.29|K-Jetronic  with  Control theory|closed-loop  Air–fuel ratio#Air.E2.80.93fuel equivalence ratio .28.CE.BB.29|lambda  control, also named Ku-Jetronic, the letter u denominating USA. The system was developed to comply with  United States|U.S.A.  Federated state|state  of  California|California's  California Air Resources Board  exhaust emission regulations, and later replaced by  Jetronic#KE-Jetronic .281985.E2.80.931993.29|KE-Jetronic .


===Pistons===
=={{anchor|KE}}KE-Jetronic (1985–1993)==
Electronically controlled mechanical fuel injection. The  engine control unit  (ECU) may be either analog or digital, and the system may or may not have closed-loop lambda control. The system is based on the K-Jetronic mechanical system, with the addition of an electro-hydraulic actuator, essentially a fuel injector inline with the fuel return. Instead of injecting fuel into the intake, this injector allows fuel to bypass the fuel distributor, which varies the fuel pressure supplied to the mechanical injection components based on several inputs (engine speed, air pressure, coolant temperature, throttle position, lambda etc.) via the ECU. With the electronics disconnected, this system will operate as a K-Jetronic system.<ref>Robert Bosch GmbH (1985). Electronically Controlled Gasoline Fuel-Injected System with Lambda Closed-Loop Control - KE-Jetronic.</ref>


===Crank/Rods===
Commonly known as 'CIS-E' in the USA. The later KE3 (CIS-E III) variant features  engine knocking|knock  sensing capabilities.


==Forced Induction==
=={{anchor|L}}L-Jetronic (1974–1989)==
You can expect between 6-10 Hp per pound of positive pressure added for most forced induction setups. All M40 variants are able to handle 6-8 PSI relatively well without any internal modifications. With just ARP head studs and a quality head gasket, an otherwise stock engine can handle 12-15 PSI relatively well.  
Analog fuel injection. L-Jetronic was often called Air-Flow Controlled (AFC) injection to further separate it from the pressure-controlled D-Jetronic &mdash; with the 'L' in its name derived from {{lang-de|luft}}, meaning 'air'. In the system, air flow into the engine is measured by a moving vane (indicating engine load) known as the  volume air flow sensor  (VAF) &mdash; referred to in German documentation as the ''LuftMengenMesser'' or LMM. L-Jetronic used custom-designed  integrated circuits , resulting in a simpler and more reliable  engine control unit  (ECU) than the D-Jetronic's.<ref>Baggeroer, Artgur B. L-Jetronic fuel injection. July 1985. General OneFile. Web. 23 July 2012.</ref>


===Turbocharging===
L-Jetronic was used heavily in 1980s-era  Europe an cars,<ref>{{cite web|author=Lee Thompson, John De Armond|title=L-Jetronic|url=http://yarchive.net/car/l-jetronic.html|format=archived  usenet  message|date=22 June 1993|access-date=17 November 2009}}</ref> as well as  BMW K100|BMW K-Series  motorcycles. Licensing some of Bosch's L-Jetronic concepts and technologies,  Lucas Automotive|Lucas ,  Hitachi, Ltd.|Hitachi Automotive Products ,  DENSO|NipponDenso , and others produced similar fuel injection systems for Asian car manufacturers. L-Jetronic manufactured under license by  JECS|Japan Electronic Control Systems  was fitted to the  Kawasaki_Kz1000|1980 Kawasaki Z1000-H1 , the world's first production fuel injected motorcycle. Despite physical similarity between L-Jetronic components and those produced under license by other manufacturers, the non-Bosch systems should not be called L-Jetronic, and the parts are usually incompatible.


===Supercharging===
=={{anchor|LE}}LE1-Jetronic, LE2-Jetronic, LE3-Jetronic (1981–1991)==
This is a simplified and more modern variant of  #L|L-Jetronic . The ECU was much cheaper to produce due to more modern components, and was more standardised than the L-Jetronic ECUs. As per L-Jetronic, a vane-type airflow sensor is used.<ref>{{cite web|title=LE-Jetronic|url=http://br.bosch-automotive.com/en/internet/parts/parts_and_accessories_2/motor_and_sytems/benzin/injection_system/le_jetronic_1/le_jetronic.html|website=www.bosch-automotive.com|access-date=23 September 2017}}</ref> Compared with L-Jetronic, the fuel injectors used by LE-Jetronic have a higher impedance.<ref>{{cite web|title=About Opel fuel injection systems|url=http://users.telenet.be/jov/opeltuners/aboutfi/ciccosinjection.html|website=www.users.telenet.be|access-date=23 September 2017}}</ref> Three variants of LE-Jetronic exist: LE1, the initial version. LE2 (1984–), featured cold start functionality integrated in the ECU, which does not require the cold start injector and thermo time switch used by older systems. LE3 (1989–), featuring miniaturised ECU with hybrid technology, integrated into the junction box of the mass airflow meter.
 
=={{anchor|LU}}LU1-Jetronic, LU2-Jetronic (1983–1991)==
The same as  #LE|LE1-Jetronic  and  #LE|LE2-Jetronic  respectively, but with closed-loop lambda control. Initially designed for the US market.
 
=={{anchor|LH}}LH-Jetronic (1982–1998)==
Digital fuel injection, introduced for California bound 1982  Volvo 240  models. The 'LH' stands for {{lang-de|"Luftmasse-Hitzdraht"}} - the  anemometer#Hot-wire anemometers|hotwire anemometer  technology used to determine the  mass  of air into the engine. This  mass flow sensor|air mass meter  is called HLM2 (''Hitzdrahtluftmassenmesser'' 2) by Bosch. The LH-Jetronic was mostly used by  Scandinavia n car manufacturers, and by sports and luxury cars produced in small quantities, such as  Porsche 928 . The most common variants are LH&nbsp;2.2, which uses an  Intel  8049 ( Intel MCS-48|MCS-48 ) microcontroller, and usually a 4&nbsp; kilobyte|kB  programme memory, and LH&nbsp;2.4, which uses a  Siemens AG|Siemens  80535 microcontroller (a variant of Intel's 8051/ Intel MCS-51|MCS-51  architecture) and 32&nbsp;kB programme memory based on the 27C256 chip. LH-Jetronic&nbsp;2.4 has adaptive lambda control, and support for a variety of advanced features; including fuel enrichment based on  exhaust gas  temperature (ex.  Volvo Redblock Engine|Volvo B204GT/B204FT engines ). Some later (post-1995) versions contain hardware support for first generation diagnostics according to  list of ISO standards#ISO 1000–ISO 9999|ISO 9141  (a.k.a.  on-board diagnostics#OBD-II|OBD-II ) and immobiliser functions. {{citation needed|reason=Volvo 940 from 1995 and on was given as an example of this, but model year -95 has the older diagnosis box in the engine compartment, and while 1996–1998 do have an OBD-II style connector, they still use the older interface, not OBD-II.|date=May 2012}}
 
=={{anchor|Mono}}Mono-Jetronic (1988–1995)==
Digital fuel injection. This system features one centrally positioned fuel injection nozzle. In the US, this kind of  fuel injection#Throttle body injection|single-point  injection was marketed as 'throttle body injection' (TBI, by GM), or 'central fuel injection' (CFI, by Ford).
 
Mono-Jetronic is different from all other known single-point systems, in that it only relies on a throttle position sensor for judging the engine load. There are no sensors for air flow, or intake manifold vacuum. Mono-Jetronic always had adaptive closed-loop lambda control, and due to the simple engine load sensing, it is heavily dependent on the lambda sensor for correct functioning.
 
The ECU uses an  Intel MCS-51|Intel 8051  microcontroller , usually with 16&nbsp;kiB of program memory and without advanced  on-board diagnostics  (OBD-II became a requirement in model-year 1996.)
 
==See also==
* Motronic
 
==References==
{{reflist}}
 
==External links==
*[https://web.archive.org/web/20100809110201/http://members.rennlist.com/pbanders/djetfund.htm History of the D-Jetronic System]
*[https://archive.is/20130415063334/http://www.k-jet.org/ Volvo enthusiasts. The site mostly focuses on 240-series cars with the Bosch K-Jet fuel injection systems]
<!-- *[http://autorepair.about.com/od/enginefuelfuelinjectio/ Fuel Injection Theory] collection of dead links-->

Revision as of 16:15, 24 February 2021

Jetronic is a trade name of a manifold injection technology for automotive petrol engine s, developed and marketed by Robert Bosch GmbH from the 1960s onwards. Bosch licensed the concept to many automotive industry|automobile manufacturers . There are several variations of the technology offering technological development and refinement.

D-Jetronic (1967–1979)

Analogue fuel injection, 'D' is from Template:Lang-de meaning pressure. Inlet manifold vacuum is measured using a pressure sensor located in, or connected to the intake manifold , in order to calculate the duration of fuel injection pulses. Originally, this system was called Jetronic, but the name D-Jetronic was later created as a retronym to distinguish it from subsequent Jetronic iterations.

D-Jetronic was essentially a further refinement of the Bendix Electrojector|Electrojector fuel delivery system developed by the Bendix Corporation in the late 1950s. Rather than choosing to eradicate the various reliability issues with the Electrojector system, Bendix instead licensed the design to Bosch. With the role of the Bendix system being largely forgotten D-Jetronic became known as the first widely successful precursor of modern electronic common rail systems; it had constant pressure fuel delivery to the injectors and pulsed injections, albeit grouped (2 groups of injectors pulsed together) rather than sequential (individual injector pulses) as on later systems.

As in the Electrojector system, D-Jetronic used Analogue electronics|analogue circuitry, with no microprocessor nor Logic gate|digital logic , the Electronic control unit|ECU used about 25 Transistor|transistors to perform all of the processing. Two important factors that led to the ultimate failure of the Electrojector system: the use of paper-wrapped capacitors unsuited to heat-cycling and amplitude modulation (AM radio) signals to control the injectors were superseded. The still present lack of processing power and the unavailability of solid-state sensors meant that the vacuum sensor was a rather expensive precision instrument, rather like a barometer , with brass bellows inside to measure the manifold pressure.

Although conceptually similar to most later systems with individual electrically controlled injectors per cylinder, and Pulse-width modulation|pulse-width modulated fuel delivery, the fuel pressure was not modulated by manifold pressure, and the injectors were fired only once per 2 revolutions on the engine (with half of the injectors being fired each revolution).

The system was last used (with a Lucas Industries|Lucas designed timing mechanism and Lucas labels super-imposed on some components) on the Jaguar V12 engine ( Jaguar XJ|XJ12 and Jaguar XJS|XJ-S ) from 1975 until 1979.

Template:AnchorK-Jetronic (1973–1994)

Mechanical fuel injection, 'K' stands for Template:Lang-de, meaning continuous. Commonly called 'Continuous Injection System (CIS) in the USA. K-Jetronic is different from pulsed injection systems in that the fuel flows continuously from all injectors, while the Fuel pump (engine)|fuel pump pressurises the fuel up to approximately 5  bar (unit)|bar (73.5  pounds per square inch|psi ). The volume of air taken in by the engine is measured to determine the amount of fuel to inject. This system has no oxygen sensor|lambda loop or lambda control. K-Jetronic debuted in the 1973.5 Porsche 911 T in January 1973, and was later installed into a number of Porsche , Volkswagen , Audi , BMW , Mercedes-Benz , List of Rolls-Royce motor cars|Rolls-Royce , Bentley , Lotus Cars|Lotus , Ferrari , Peugeot , Nissan , Renault , Volvo Cars|Volvo , Saab Automobile|Saab , TVR and Ford automobiles. The final car to use K-Jetronic was the 1994 Porsche 911 Turbo 3.6.

Fuel is pumped from the tank to a large control valve called a fuel distributor, which divides the single fuel supply line from the tank into smaller lines, one for each injector. The fuel distributor is mounted atop a control vane through which all intake air must pass, and the system works by varying fuel volume supplied to the injectors based on the angle of a Mass flow sensor#Moving vane meter|moving vane in the air flow meter , which in turn is determined by the volume of air passing the vane, and by the control pressure. The control pressure is regulated with a mechanical device called the control pressure regulator (CPR) or the warm-up regulator (WUR). Depending on the model, the CPR may be used to compensate for altitude, full load, and/or a cold engine. The injectors are simple spring-loaded check valve s with nozzles; once fuel system pressure becomes high enough to overcome the counterspring, the injectors begin spraying.

Template:AnchorK-Jetronic (Lambda)

First introduced in the Volvo 240|Volvo 265 in 1976 and later used in the DeLorean Motor Company|DeLorean in 1981. A variant of Jetronic#K-Jetronic .281973.E2.80.931994.29|K-Jetronic with Control theory|closed-loop Air–fuel ratio#Air.E2.80.93fuel equivalence ratio .28.CE.BB.29|lambda control, also named Ku-Jetronic, the letter u denominating USA. The system was developed to comply with United States|U.S.A. Federated state|state of California|California's California Air Resources Board exhaust emission regulations, and later replaced by Jetronic#KE-Jetronic .281985.E2.80.931993.29|KE-Jetronic .

Template:AnchorKE-Jetronic (1985–1993)

Electronically controlled mechanical fuel injection. The engine control unit (ECU) may be either analog or digital, and the system may or may not have closed-loop lambda control. The system is based on the K-Jetronic mechanical system, with the addition of an electro-hydraulic actuator, essentially a fuel injector inline with the fuel return. Instead of injecting fuel into the intake, this injector allows fuel to bypass the fuel distributor, which varies the fuel pressure supplied to the mechanical injection components based on several inputs (engine speed, air pressure, coolant temperature, throttle position, lambda etc.) via the ECU. With the electronics disconnected, this system will operate as a K-Jetronic system.<ref>Robert Bosch GmbH (1985). Electronically Controlled Gasoline Fuel-Injected System with Lambda Closed-Loop Control - KE-Jetronic.</ref>

Commonly known as 'CIS-E' in the USA. The later KE3 (CIS-E III) variant features engine knocking|knock sensing capabilities.

Template:AnchorL-Jetronic (1974–1989)

Analog fuel injection. L-Jetronic was often called Air-Flow Controlled (AFC) injection to further separate it from the pressure-controlled D-Jetronic — with the 'L' in its name derived from Template:Lang-de, meaning 'air'. In the system, air flow into the engine is measured by a moving vane (indicating engine load) known as the volume air flow sensor (VAF) — referred to in German documentation as the LuftMengenMesser or LMM. L-Jetronic used custom-designed integrated circuits , resulting in a simpler and more reliable engine control unit (ECU) than the D-Jetronic's.<ref>Baggeroer, Artgur B. L-Jetronic fuel injection. July 1985. General OneFile. Web. 23 July 2012.</ref>

L-Jetronic was used heavily in 1980s-era Europe an cars,<ref>Template:Cite web</ref> as well as BMW K100|BMW K-Series motorcycles. Licensing some of Bosch's L-Jetronic concepts and technologies, Lucas Automotive|Lucas , Hitachi, Ltd.|Hitachi Automotive Products , DENSO|NipponDenso , and others produced similar fuel injection systems for Asian car manufacturers. L-Jetronic manufactured under license by JECS|Japan Electronic Control Systems was fitted to the Kawasaki_Kz1000|1980 Kawasaki Z1000-H1 , the world's first production fuel injected motorcycle. Despite physical similarity between L-Jetronic components and those produced under license by other manufacturers, the non-Bosch systems should not be called L-Jetronic, and the parts are usually incompatible.

Template:AnchorLE1-Jetronic, LE2-Jetronic, LE3-Jetronic (1981–1991)

This is a simplified and more modern variant of #L|L-Jetronic . The ECU was much cheaper to produce due to more modern components, and was more standardised than the L-Jetronic ECUs. As per L-Jetronic, a vane-type airflow sensor is used.<ref>Template:Cite web</ref> Compared with L-Jetronic, the fuel injectors used by LE-Jetronic have a higher impedance.<ref>Template:Cite web</ref> Three variants of LE-Jetronic exist: LE1, the initial version. LE2 (1984–), featured cold start functionality integrated in the ECU, which does not require the cold start injector and thermo time switch used by older systems. LE3 (1989–), featuring miniaturised ECU with hybrid technology, integrated into the junction box of the mass airflow meter.

Template:AnchorLU1-Jetronic, LU2-Jetronic (1983–1991)

The same as #LE|LE1-Jetronic and #LE|LE2-Jetronic respectively, but with closed-loop lambda control. Initially designed for the US market.

Template:AnchorLH-Jetronic (1982–1998)

Digital fuel injection, introduced for California bound 1982 Volvo 240 models. The 'LH' stands for Template:Lang-de - the anemometer#Hot-wire anemometers|hotwire anemometer technology used to determine the mass of air into the engine. This mass flow sensor|air mass meter is called HLM2 (Hitzdrahtluftmassenmesser 2) by Bosch. The LH-Jetronic was mostly used by Scandinavia n car manufacturers, and by sports and luxury cars produced in small quantities, such as Porsche 928 . The most common variants are LH 2.2, which uses an Intel 8049 ( Intel MCS-48|MCS-48 ) microcontroller, and usually a 4  kilobyte|kB programme memory, and LH 2.4, which uses a Siemens AG|Siemens 80535 microcontroller (a variant of Intel's 8051/ Intel MCS-51|MCS-51 architecture) and 32 kB programme memory based on the 27C256 chip. LH-Jetronic 2.4 has adaptive lambda control, and support for a variety of advanced features; including fuel enrichment based on exhaust gas temperature (ex. Volvo Redblock Engine|Volvo B204GT/B204FT engines ). Some later (post-1995) versions contain hardware support for first generation diagnostics according to list of ISO standards#ISO 1000–ISO 9999|ISO 9141 (a.k.a. on-board diagnostics#OBD-II|OBD-II ) and immobiliser functions. Template:Citation needed

Template:AnchorMono-Jetronic (1988–1995)

Digital fuel injection. This system features one centrally positioned fuel injection nozzle. In the US, this kind of fuel injection#Throttle body injection|single-point injection was marketed as 'throttle body injection' (TBI, by GM), or 'central fuel injection' (CFI, by Ford).

Mono-Jetronic is different from all other known single-point systems, in that it only relies on a throttle position sensor for judging the engine load. There are no sensors for air flow, or intake manifold vacuum. Mono-Jetronic always had adaptive closed-loop lambda control, and due to the simple engine load sensing, it is heavily dependent on the lambda sensor for correct functioning.

The ECU uses an Intel MCS-51|Intel 8051 microcontroller , usually with 16 kiB of program memory and without advanced on-board diagnostics (OBD-II became a requirement in model-year 1996.)

See also

  • Motronic

References

Template:Reflist

External links