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. The complete system contains the following components. The fuel injection system improved the fuel efficiency, engine performance and lessened the emissions. Bosch l jetronic fuel injection manual volkswagen type2vanagon d jetronic fuel injection pro training manual. L jetronic is a boschmanufactured electronic fuel injection featured on many early 80s cars. This was a microsoft powerpoint document, presented at the 1999 e12 fall fest in virginia beach, va. One of the most important parameters of the djet and any other fuel injection system for that matter. 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. What an electronic system offers is precise control over fuel delivery and air flow.
Between the years 1973 and 1995, the highly reliable, mechanical multipoint injection system kjetronic was installed as original equipment in seriesproduction vehicles. 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. Djetronic history and fundamentals history the djetronic system developed by bosch in the early 1960s was the first massproduction electronic fuel injection system. If in doubt, spray break cleaner on pipes, hoses, injectors, intake manifold and map sensor. 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. Automotive equipment business sector, department for automotive services, technical publications khpdi2. Find out how fuel injection systems work and about the various configurations used in the cars today. 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. This pulsed system was partly designed by volkswagen, but operates pretty much as bosch motronic does. Bosch k jetronic fuel injection manual pdf document.
The average system pressure on all k jetronic fuel systems should be 520 kpa. Chapter of d jetronic articles by drdjet describes systematic fault finding troubleshooting and repair on your bosch fuel injection system. 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. 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. It wont be as good as a modern fuel injection system like motec, but it will work. Chapter of djetronic articles by drdjet describes systematic fault finding troubleshooting and repair on your bosch fuel injection system. The l jetronic was the first massproduced, fully electronic fuel injection system. Some, however, use a vane type fuel pump mounted directly to the injection pumpfuel distributor assembly. This manual describes the ljetronic and its most important features. For those not familiar with bosch ljetronic fuel injection you may want to start with l jetronic seminar in pdf format. As djetronic could only handle 8 cylinders, it was modified by lucas. 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. The last carburetorequipped car came off the assembly line in 1990. In the lejetronic system, the injection valves spray the fuel simultaneously, what is to say, they are all driven at the same time.
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. 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. The former system is called multiport fuel injection and. L jetronic, lh jetronic, and motronicasanintegratedenginemanagement system. Testing unit in the car, trying to start the car after rebuild. For a gasoline engine, fuel pressure is usually on the order of 3550 psi. Most fuel injection systems are for gasoline or diesel. Idle switch is used for coasting fuelcutoff on later modelse12 7981. Gasoline fuel injection system ljetronic bosch pdf download this manual may contain attachments and optional equipment that are not available in your. Combining this direct injection theory with electronic sensors, valves. Fuel injection system the ke2 jetronic fuel injection system is fitted to turbocharged engines. It will also cover trouble shooting and performance tips table contents of ljetronic fuel injection systems for bmw e12s. 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.
While port injection systems such as ke and ljetronic employ a separate injector for each cylinder, monojetronic features a single, centrallylocated, solenoidcon. After that jaguar had to find another solution for their 12 cylinder that was finally installed from 1975 to 1980. Tuning out my fuel injection on a opel kadett utilizing a gas meter part 3. The fall of the carburetor how fuel injection systems work. Ljetronic fuel injection technical troubleshooting article. Bendix developed the basic idea of using an inductive element coupled to manifold vacuum as a. This following overview is a brief description of the system. Apart from minor alterations the basic principles of the hydraulics and mechanics used on the kjetronic system are unchanged on the kejetronic system. Gasoline fuel injection system ljetronic bosch pdf. Gasolineengine management gasoline fuelinjection system kjetronic technical instruction published by. Deviations from this ratio affect engine operation.
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. It combines ljetronic pulsed fuel injection with electronic ignition timing control in one control unit. Bosch superseded the djetronic system with the kjetronic and ljetronic systems for 1974, though some cars such as the volvo 164 continued. It is quite straightforward in its operation, providing diagnosis and testing is acrried out logically and one step at. The bosch d jetronic fuel injection system was used by vw in the type iii in 1968. Aug 18, 20 the l jetronic is an electronically controlled fuel injection system which has the advantage of direct air flow sensing. In the case of the ljetronic, the amount of air drawn in by the. This seminar will describe the ljetronic system fitted on e12s. 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. It was primarily based on patents that bosch licensed from the bendix corporation. The system pressure of the k jetronic can not be reduced like an efi system when cleaning with our lb2912f flow meter. Advantages of the direct petrol injection system this system offers fuel savings of up to 15% in volk swagen vehicles. 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. Direct petrol injection system with bosch motronic med 7.
General information and precautions bosch kjetronic and ke. In other words, 15 kg of air are required for complete combustion of 1 kg of gasoline stoichiometric ratio. The bosch ljetronic fuel injection system is electronically controlled to regulate the fuel supply in relation to the air flow. Robert bosch gmbh, 2000 postfach 30 02 20, d70442 stuttgart. 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. The ljetronic is an electronically controlled fuel injection system which has the advantage of direct air flow sensing. In most engines, it also has electronic idle stabilization for a complete enginemanagement system. The mechanical fuel injection system has recently been overshadowed by modern electronic injection, which enables the use of lambda closed loop control. Everyday low prices and free delivery on eligible orders. This was the first electronic fuel injection system to be fitted to a production car.
The individual factors contributing to these savings are presented on the next two pages. Ljetronic principle with electronic mapcontrolled ignition. 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. The engines fuel requirements a sparkignition engine needs a particular air fuel ratio in order to operate. The electronically modified bosch ke also has this capability although it never achieved the popularity of the pure mechanical system. Bosch ljetronic fuel injection manual volkswagen type2vanagon djetronic fuel injection pro training manual. It differentiates from the le jetronic for having, in addition to the injection system, also the ignition system incorporated in the command unit. Bosch k jetronic mechanical fuel injection troubleshooter. 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. See pages 286292 for important safety, emissions and warranty information. Fuel injection system the ke2jetronic fuel injection system is fitted to turbocharged engines. Now let us have a look how bosch kejetronic fuel injection system can be diagnosed and repaired on an example of audi 100 2. Vw ljetronic fuel injection workshop manual created date. Since then, fuel injectors have been the primary means of getting gasoline into the engine cylinder so it can combust and you can drive.
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. Bosch ljetronic system on the fiat 1500cc engine how ljetronic works this basic operation is achievable without an electronic fuel injection system. 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. Until 1996, this fuelinjection system was installed as an independent system in seriesproduction vehicles, and in this. 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. The ljetronic is an electronically controlled fuelinjection system.
Detach the operational relay set from the relay block as well as from the safety appliance located under the steering tube. Some, however, use a vane type fuel pump mounted directly to the injection pump fuel distributor assembly. As d jetronic could only handle 8 cylinders, it was modified by lucas. Pfi port fuel injection gdi gasoline direct injection in north america. 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. Bosch gasoline fuel injection system ljetronic book. Vw ljetronic fuel injection workshop manual author. Domestic carmakers adopted electronic fuel injection extensively on breadandbutter production cars in the early 80s. Bosch licensed the concept to many automobile manufacturers. Fuel injection is a system for admitting fuel into an internal combustion engine. 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.
Certain operating conditions make it necessary to correct the mixture accordingly. 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. A fuel injection system is designed and calibrated specifically for the types of fuel it will handle. Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. 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. 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. I hope i have covered all the problem areas and lifted some of the mist surrounding this system. 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. Many of them use a fuel pump essentially identical to the carbureted fuel system s. There are several variations of the technology offering technological development and refinement. Ljetronic fuel pressure testing itinerant aircooled. 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. 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.
It has become the primary fuel delivery system used in automotive petrol engines, having almost completely replaced carburetors during the late 1980s. Fuel delivery system certain mechanical fuel injection systems also utilize a mechanical fuel pump, typically some early gasoline fuel injection systems. Dethrottling in stratified charge mode and homogeneous lean charge mode in these operating modes, the vehicle operates at. Gasoline fuel injection system ljetronic bosch pdf download this manual may contain attachments and optional equipment that are not available in. 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. Ljetronic the bosch ljetronic also called afcair flow controlled fuel injection was put into usspec type 4s in the last model year 1974. The biggest problem will be the engine leaning out at high rpm. Bosch kejetronic system the bosch kejetronic fuelinjection system is fitted to escort rs turbo models and is a further development of the kjetronic system. The system is used in conjunction with a turbocharger on rs turbo models. Examples home mechanical fuel injection volvo owners club. Bosch ljetronic fuel injection guide fiat fuel injected. This is basically the kjetronic fuel injection system.
Ljetronic, lhjetronic, and motronicasanintegratedenginemanagement 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. The task of a fuel injection system is to supply precise amount of fuel to the combustion chamber at that particular moment. Prior to l jetronic, mechanical fuel injection systems had proven that directly injecting atomized fuel into the cylinder resulted in better engine operation. 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. It features a lambda probe aggregated to the injection system, installed in the exhaust pipe. Today, it has been superseded by gasoline injection. Tuning out my fuel injection on a opel kadett utilizing a gas meter part 1. 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. Petrol engines can use gasoline direct injection, where the fuel is directly delivered into the combustion chamber, or indirect injection where the fuel is. Latest trends in automotive electronic systems highway.
Bosch kjetronic fuel injection part 1 volvo owners club. 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. Monojetronic fuelinjection system system overview monojetronic is an electronically controlled, lowpressure, singlepoint injection spi system for 4cylinder engines. Then, the command unit processes this information received and calculate the appropriate fuel injection time, through an electric signal. The bosch fuel injection systems 19701979 shop manual published by carbooks, inc. 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. Many of them use a fuel pump essentially identical to the carbureted fuel systems.