While new carburated engines were used in the european markets, vw adapted the ljetronic for the type 4 in the us due to more stringent emissions and fuel consumption regulations. Fuel injection systems after the gasoline travel all the way from the tank, passing all the equipment before, it is deliver to the equipment that is responsible from mixing the fuel whit the air, and supplying the fuel to the engine. Tuning out my fuel injection on a opel kadett utilizing a gas meter part 3. The earliest bosch installations were the djetronic and ljetronic systems, and we can still find their operating principles at work in vehicles for the 2001 model year. Detach the operational relay set from the relay block as well as from the safety appliance located under the steering tube. It wont be as good as a modern fuel injection system like motec, but it will work. The only vehicle that runs a higher pressure than this is the porsche turbo carrara models from 1975 to 1979 which have a system pressure of 600 kpa. Bosch l jetronic fuel injection manual volkswagen type2vanagon d jetronic fuel injection pro training manual.
The average system pressure on all k jetronic fuel systems should be 520 kpa. Fuel injection system the ke2 jetronic fuel injection system is fitted to turbocharged engines. The afc fuel injection system also contains a feedback system which measures oxygen content of exhaust gases and maintains the air fuel ratio at about 14. Bosch k jetronic mechanical fuel injection troubleshooter. It has become the primary fuel delivery system used in automotive petrol engines, having almost completely replaced carburetors during the late 1980s. Bosch kejetronic system the bosch kejetronic fuelinjection system is fitted to escort rs turbo models and is a further development of the kjetronic system. Gasoline fuel injection system ljetronic bosch pdf. Gas engines can use gasoline direct injection, where the fuel is directly delivered into the combustion chamber, or indirect injection where the fuel is mixed with air before the intake stroke. Nov 21, 2009 gasoline engine management gasoline fuel injection system k jetronic technical instruction slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Today, it has been superseded by gasoline injection. The fuel injection system consists of an electric fuel pump, fuel pressure regulator, fuel damper, fuel injectors, cold start injector, electronic control unit ecu, and airflow meter. The bosch ljetronic fuel injection system is electronically controlled to regulate the fuel supply in relation to the air flow. The ljetronic is an electronically controlled fuel injection system which has the advantage of direct air flow sensing.
Between the years 1973 and 1995, the highly reliable, mechanical multipoint injection system kjetronic was installed as original equipment in seriesproduction vehicles. Ljetronic system air mass measurement n fuel injection system has to know mass of air n airflow meter provides air mass flow information u mass is calculated by volume flow and density f need device to determine flow air flap on airflow meter f need temperature to determine density temperature sensor in air flow meter afm 1. If you plan to supercharger or turbocharge your vehicle using the stock l jetronic fuel injection system i can assure you it can be done with minimal work and expense. The engines fuel requirements a sparkignition engine needs a particular air fuel ratio in order to operate. Certain operating conditions make it necessary to correct the mixture accordingly. Testing unit in the car, trying to start the car after rebuild. This pulsed system was partly designed by volkswagen, but operates pretty much as bosch motronic does.
Ljetronic fuel pressure testing itinerant aircooled. While port injection systems such as ke and ljetronic employ a separate injector for each cylinder, monojetronic features a single, centrallylocated, solenoidcon. Bosch superseded the djetronic system with the kjetronic and ljetronic systems for 1974, though some cars such as the volvo 164 continued. In other words, 15 kg of air are required for complete combustion of 1 kg of gasoline stoichiometric ratio.
The last carburetorequipped car came off the assembly line in 1990. As djetronic could only handle 8 cylinders, it was modified by lucas. The basic l jetronic consists of a fuel pump, fuel filter, fuel lines, fuel regulator, fuel injectors, coldstart injector could be omitted on some l s, thermotime switch, coolant temperature sensor, auxiliary air valve, throttle plate and an airflow sensor flap type in analog l s discussed here. Chapter of djetronic articles by drdjet describes systematic fault finding troubleshooting and repair on your bosch fuel injection system. Nov 27, 2014 ae brico from coventry had also started to develop a bendix based fuel injection system for jaguars 12 cylinder, but ceased its development in 1970. When pressure is constant, as well as the injector orifice it is being metered through, the duration injector is open is the remaining variable by which fuel amount. What an electronic system offers is precise control over fuel delivery and air flow. The biggest problem will be the engine leaning out at high rpm. Thisis necessary due to the added complexity and increased power output of the engine, the system provides a higher degree of mixture strength control than that provided by the k jetronic system. One of the most important parameters of the djet and any other fuel injection system for that matter. Originally, volkswagen adapted the ljetronic for the type 4 air cooled 411 engines sold in the united states due to more stringent emissions and fuel consumption regulations. Now let us have a look how bosch ke jetronic fuel injection system can be diagnosed and repaired on an example of audi 100 2.
Gasoline injection systems overview 10 k jetronic system overview fuel supply 14 fuel metering 18 adapting to operating conditions 24 supplementary functions 30 exhaustgas treatment 32 electrical circuitry 36 workshop testing techniques 38 k jetronic since its introduction, the k jetronic gasoline injection system has pro. Bosch developed an electronic fuel injection system, called djetronic d for druck, german for pressure, which was first used on the vw 1600tle in 1967. Fuel injection system the ke2jetronic fuel injection system is fitted to turbocharged engines. L jetronic electronic control unit ecu, airflow sensor, system relay, fuel pump relay, lambdasond oxygen sensor, vacuum switch, electric fuel pump, coolant temperature sensor, fuel injectors, and the electronic control unit terminal for the constant idle systems cis if equipped. Ljetronic, lhjetronic, and motronicasanintegratedenginemanagement system.
The ljetronic is an electronically controlled fuelinjection system. It features a lambda probe aggregated to the injection system, installed in the exhaust pipe. Latest trends in automotive electronic systems highway. Automotive equipment business sector, department for automotive services, technical publications khpdi2.
Ljetronic the bosch ljetronic also called afcair flow controlled fuel injection was put into usspec type 4s in the last model year 1974. The fuel injection system improved the fuel efficiency, engine performance and lessened the emissions. Then, the command unit processes this information received and calculate the appropriate fuel injection time, through an electric signal. Robert bosch gmbh, 2000 postfach 30 02 20, d70442 stuttgart. Some, however, use a vane type fuel pump mounted directly to the injection pump fuel distributor assembly. Gasoline can be injected either externally in the inlet manifold where it gets mixed with the air before being delivered to the combustion chamber, or directly inside the combustion chamber. Find out how fuel injection systems work and about the various configurations used in the cars today.
Bosch announced a more advanced system, l jetronic, in 1972 and the writer remembers a v12 jaguar saloon equipped with a dual version, one per bank, in 1974 or thereabouts, anticipating bmws similar dual motronic arrangement of their more recent v12 by many years. Bosch ljetronic fuel injection guide fiat fuel injected. Bosch k jetronic fuel injection manual pdf document. This seminar will describe the ljetronic system fitted on e12s. Bosch kjetronic fuel injection part 1 volvo owners club. Everyday low prices and free delivery on eligible orders. The l jetronic was the first massproduced, fully electronic fuel injection system. The bosch d jetronic fuel injection system was used by vw in the type iii in 1968. Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector.
Bosch ljetronic fuel injection manual volkswagen type2vanagon djetronic fuel injection pro training manual. Deviations from this ratio affect engine operation. For those not familiar with bosch ljetronic fuel injection you may want to start with l jetronic seminar in pdf format. Ae brico from coventry had also started to develop a bendix based fuel injection system for jaguars 12 cylinder, but ceased its development in 1970. An air flow meter, located in the air intake chamber, converts angular movement of an air baffle plate into a voltage signal, which is sent to the control unit. Gasoline fuel injection system ljetronic bosch pdf download this manual may contain attachments and optional equipment that are not available in your.
This is basically the kjetronic fuel injection system. Ljetronic system throttle and idle control n throttle opens to allow more air to sucked in to engine n small amount of air bypasses the throttle so the engine gets air and will idle. Prior to l jetronic, mechanical fuel injection systems had proven that directly injecting atomized fuel into the cylinder resulted in better engine operation. This was a microsoft powerpoint document, presented at the 1999 e12 fall fest in virginia beach, va. The task of a fuel injection system is to supply precise amount of fuel to the combustion chamber at that particular moment. This manual describes the ljetronic and its most important features. In the lejetronic system, the injection valves spray the fuel simultaneously, what is to say, they are all driven at the same time. If in doubt, spray break cleaner on pipes, hoses, injectors, intake manifold and map sensor. Combining this direct injection theory with electronic sensors, valves. In the case of the ljetronic, the amount of air drawn in by the. The system pressure of the k jetronic can not be reduced like an efi system when cleaning with our lb2912f flow meter. Pfi port fuel injection gdi gasoline direct injection in north america. Ljetronic principle with electronic mapcontrolled ignition.
Vw ljetronic fuel injection workshop manual author. Djetronic history and fundamentals history the djetronic system developed by bosch in the early 1960s was the first massproduction electronic fuel injection system. It will also cover trouble shooting and performance tips table contents of ljetronic fuel injection systems for bmw e12s. It is quite straightforward in its operation, providing diagnosis and testing is acrried out logically and one step at. Singlepoint fuel injection singlepoint throttlebody injection tbi fuel injection is the concept behind this electronicallycontrolled injection system in which a centrally located solenoidoperated injection valve mounted upstream from the throttle. L jetronic is a boschmanufactured electronic fuel injection featured on many early 80s cars. This following overview is a brief description of the system. The complete system contains the following components. Gasolineengine management gasoline fuelinjection system kjetronic technical instruction published by. Direct petrol injection system with bosch motronic med 7.
I hope i have covered all the problem areas and lifted some of the mist surrounding this system. R02cr e b colqegu couivo\ aglase we guq ph ph ecn le logq coucvtloue eae16uj sqgble 10 cugua vqsblsqou ob6lguua couqguoue guq nuq6l bgl11cr1gl logq. Gasolineinjection systems overview 10 kjetronic system overview fuel supply 14 fuel metering 18 adapting to operating conditions 24 supplementary functions 30 exhaustgas treatment 32 electrical circuitry 36 workshop testing techniques 38 kjetronic since its introduction, the kjetronic gasolineinjection system has pro. After that jaguar had to find another solution for their 12 cylinder that was finally installed from 1975 to 1980. A fuel injection system is designed and calibrated specifically for the types of fuel it will handle. Ljetronic fuel injection technical troubleshooting article. Most fuel injection systems are for gasoline or diesel. Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector all diesel engines use fuel injection by design. Advantages of the direct petrol injection system this system offers fuel savings of up to 15% in volk swagen vehicles. It differentiates from the le jetronic for having, in addition to the injection system, also the ignition system incorporated in the command unit.
Bosch gasoline fuel injection system ljetronic book. Vw ljetronic fuel injection workshop manual created date. Gasoline fuel injection system ljetronic bosch pdf download this manual may contain attachments and optional equipment that are not available in. It combines ljetronic pulsed fuel injection with electronic ignition timing control in one control unit. Fuel delivery system certain mechanical fuel injection systems also utilize a mechanical fuel pump, typically some early gasoline fuel injection systems. Thisis necessary due to the added complexity and increased power output of the engine, the system provides a higher degree of mixture strength control than that provided by the kjetronic system. In most engines, it also has electronic idle stabilization for a complete enginemanagement system. Description technical instruction booklet on the ljetronic fuel injection system written by bosch use this book to get to the bottom of your poor cold starting, reluctance to hot restart and to improve your general understanding and knowledge of how your porsche fuel injection system works. Fuel injection is a system for admitting fuel into an internal combustion engine. Since then, fuel injectors have been the primary means of getting gasoline into the engine cylinder so it can combust and you can drive. The former system is called multiport fuel injection and. There are several variations of the technology offering technological development and refinement. Bendix developed the basic idea of using an inductive element coupled to manifold vacuum as a. The individual factors contributing to these savings are presented on the next two pages.
Domestic carmakers adopted electronic fuel injection extensively on breadandbutter production cars in the early 80s. Combustion in the gasoline engine the sparkignition or ottocycle engine 2 gasoline engine management technical requirements 4 cylinder charge 5 mixture formation 7 ignition function and requirements 10 inductive ignition systems gasoline injection systems overview 16 mmotronic engine management mmotronic. It was primarily based on patents that bosch licensed from the bendix corporation. If you plan to supercharger or turbocharge your vehicle using the stock ljetronic fuel injection system i can assure you it can be done with minimal work and expense. As d jetronic could only handle 8 cylinders, it was modified by lucas. The bosch fuel injection systems 19701979 shop manual published by carbooks, inc.
Aug 18, 20 the l jetronic is an electronically controlled fuel injection system which has the advantage of direct air flow sensing. Bosch ljetronic system on the fiat 1500cc engine how ljetronic works this basic operation is achievable without an electronic fuel injection system. Jetronic is a trade name of a fuel injection technology for automotive petrol engines, developed and marketed by robert bosch gmbh from the 1960s onwards. Idle switch is used for coasting fuelcutoff on later modelse12 7981. So, technically, the engine only needs a 19 lbhr fuel injector to support 300 hp, but this will require that the injector is at nearly a 100% duty cycle in. Bosch licensed the concept to many automobile manufacturers. Many of them use a fuel pump essentially identical to the carbureted fuel system s. Some, however, use a vane type fuel pump mounted directly to the injection pumpfuel distributor assembly. This was the first electronic fuel injection system to be fitted to a production car.
Until 1996, this fuelinjection system was installed as an independent system in seriesproduction vehicles, and in this. General information and precautions bosch kjetronic and ke. Examples home mechanical fuel injection volvo owners club. The fall of the carburetor how fuel injection systems work. Dethrottling in stratified charge mode and homogeneous lean charge mode in these operating modes, the vehicle operates at. The system is used in conjunction with a turbocharger on rs turbo models.
The mechanical fuel injection system has recently been overshadowed by modern electronic injection, which enables the use of lambda closed loop control. For a gasoline engine, fuel pressure is usually on the order of 3550 psi. Now let us have a look how bosch kejetronic fuel injection system can be diagnosed and repaired on an example of audi 100 2. The electronically modified bosch ke also has this capability although it never achieved the popularity of the pure mechanical system. Monojetronic fuelinjection system system overview monojetronic is an electronically controlled, lowpressure, singlepoint injection spi system for 4cylinder engines. General information the fuel system comprises a centrally mounted fuel tank, electricallyoperated fuel pump and bosch k jetronic or ke jetronic continuous injection system according to model. The bosch ljetronic fuel injection system used in the porsche 912e is often referred to as the air flow controlled or afc fuel injection system.
Apart from minor alterations the basic principles of the hydraulics and mechanics used on the kjetronic system are unchanged on the kejetronic system. Tuning out my fuel injection on a opel kadett utilizing a gas meter part 1. See pages 286292 for important safety, emissions and warranty information. L jetronic, lh jetronic, and motronicasanintegratedenginemanagement system.
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