The ljetronic was the first massproduced, fully electronic fuel injection system. 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. Jetronic controls fuel supply while the electronic ignition system provides optimal ignition control. For those not familiar with bosch l jetronic fuel injection you may want to start with l jetronic seminar in pdf format. 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. The fuel pump, located in the fuel tank, pumps the fuel through a filter to the single fuel injector. These fuel injection systems were considered to be really reliable and trustworthy. But wedidnt anticipate the ravages offuel con tamination. Mono jetronic fuel injection system system overview mono jetronic is an electronically controlled, lowpressure, singlepoint injection spi system for 4cylinder engines. Djet opens the injectors the opposite way from l jet. 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 proved itself in millions of vehicles. Download technical manual l jetronic fuel injection system porsche 912e book pdf free download link or read online here in pdf. When the ignition is switched on, voltage is applied to the fuel injection relay.
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 proved itself in millions of vehicles. Fuel injection system the ke2jetronic fuel injection system is fitted to turbocharged engines. Compared with ljetronic, the fuel injectors used by le. Vw ljetronic fuel injection workshop manual created date. Lele2lu a 010902021 9705 3 system description system description general the lele2lu jetronic system is a development of the earlier bosch ljetronic fuel injection system. Prior to ljetronic, mechanical fuel injection systems had proven that directly injecting atomized fuel into the cylinder resulted in better engine operation. Monojetronic fuelinjection system system overview monojetronic is an electronically controlled, lowpressure, singlepoint injection spi system for 4cylinder engines. 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. The ecu was much cheaper to produce due to more modern components, and was more standardised than the ljetronic ecus. Many bmw vehicles were equipped with bosch l jetronic from the mid. C ge wc ujsiu coucl0116q agugplg qncjeq pi we welepa egkalua dnsuqch lus ugb e6lje0l logq b6lujte uj.
In 1985 mercedesbenz and others switched to kejetronic where electronics was back. The l jetronic aod ils variants are electro nically controlled fuelinjection systems solenoidopersle injection bosch k jetronic, bosch k jetronic fig. Electronic pulsed fuel injections systems are complex and are not a topic for backyard mechanics. The electronic control unit ecu, which is triggered by the ignition circuit, sends. Le1jetronic, le2jetronic, le3jetronic 19811991 this is a simplified and more modern variant of ljetronic. Nov 21, 2009 fuel injection although current systems rely almost although the kjetronic layout served as exclusively on mixture formation outside the mechanical basis for the kejetronic the combustion chamber, concepts based system, the latter employs expanded on internal mixture formation with fuel datamonitoring functions for more being injected. Onsomel jetronic systems, the air temperature sen sor is visible in the air flow meter inlet. The same could happen with pdf, jpg, mp3, etc, if the app didnt load the data correctly. This synthesis, comprising the mechanical basic functions coupled with electronic adaptation and optimization functions is the. Bosch k jetronic fuel injection manual linkedin slideshare. Introduced in for model year it was first installed on some of the last models 17 19 like the 2. Ljetronic the bosch ljetronic also called afcair flow controlled fuel injection was put into usspec type 4s in the last model year 1974. The dedicated shade tree mechanic can do it, but needs to be wellinformed first. These adjustments are intended to be followed by an.
Most people blame ignition system problems on the fuel injection and go on a parts. Kjetronic cis fuel system diagram shown below is a schematic diagram of fuel lines in a kjetronic as a whole with noise damper and drain line at the fuel accumulator. There are always questions posted about how to cure hard starting, hot or cold. The l jetronic aod ils variants are electro nically controlled fuelinjection systems solenoidopersle files. In reality, the ljetronic system is very simple, very reliable, and easy to diagnose. All books are in clear copy here, and all files are secure so dont worry about it. Fuel injection system the ke2 jetronic fuel injection system is fitted to turbocharged engines. As per ljetronic, a vanetype airflow sensor is used. I have done a rough translation of the scholl article that is in text file format. Gregs bosch ljetronic fuel injection idle adjustment, diagnostic and tune up page, latest revision sept. If the inlet air temperature sensor fails its resistance tests, you cant service just the sensor. While port injection systems such as ke and l jetronic employ a separate injector for each cylinder, mono jetronic features a single, centrallylocated, solenoidcon. Bosch le jetronic bmw copyright equiptech boschlejetronic thereismuchconfusionabouttheactualtypeofinjectionsystemfittedtomanybmwmotorcarsduringtheperiod1980to. Robert bosch ljetronic efi system using mostly common workshop tools.
Motronic as an integrated engine manage ment system. Basically, it is pretty similar to the kjetronic with some changes and modifications. Disconnect the return line from the distributor head 6a, and connect a hose from the distributor head outlet to the bottom of the auxiliary fuel tank 2a. Combining this direct injection theory with electronic sensors, valves. L jetronic adventure injectors not firing pelican parts. A computer controls the injection and ignition systems with reference to shared optimization criteria. Considerable fuel enrichment is required for a period of time after a cold start. If in doubt, spray break cleaner on pipes, hoses, injectors, intake manifold and map sensor. With this porsche 924 workshop manual, you can perform every job that could be done by porsche garages and mechanics from. The lele2lu jetronic system is a development of the earlier bosch ljetronic fuel injection system. Read online technical manual l jetronic fuel injection system porsche 912e book pdf free download link book now. Chapter of d jetronic articles by drdjet describes systematic fault finding troubleshooting and repair on your bosch fuel injection system. In 1978 ljetronic was the first system with lambda controlled closed loop control.
For those not familiar with bosch ljetronic fuel injection you may want to start with l jetronic seminar in pdf format. The bentely manual does an excellent job of explaining fi diagnostic procedures. Ljetronic was often called airflow controlled afc injection to further separate it from. Gregs bosch l jetronic fuel injection idle adjustment, diagnostic and tune up page, latest revision sept. Ljetronic system throttle and idlewot switches idle switch is used for coasting fuel cutoff on later modelse12 79 81. While port injection systems such as ke and ljetronic employ a separate injector for each cylinder, monojetronic features a single, centrallylocated, solenoidcon.
The following table is a guide to the fuel paths marked by each blue arrow in figure 6. Mercedes suggests that special tools are required to adjust the mixture on the bosch ke3jetronic cise fuel injection, such as is used on the 198891 560 series motors. Even kjetronic did not manage to withhold electronics. Digital data processing and microprocessors make it possible to translate extensive operating. Hookup the auxiliary fuel tank and fittings as shown on page 4. Le is the german designation of the european version of their air flow meter, with lu being the designation. These adjustments are intended to be followed by an actual exhaust gas co check to ensure. Bosch ljetronic fuel injection brandeis university. Jetronic is a trade name of a fuel injection technology for automotive petrol engines, developed. Bosch l jetronic fuel injection troubleshooting, maintenance. This was a microsoft powerpoint document, presented at the 1999 e12 fall fest in virginia beach, va. All you need for diagnostic tools is a fuel pressure gauge and a multimeter, and a manual. Vw ljetronic fuel injection workshop manual author. Djet leaves the injectors grounded all the time, and the ecu sends power to them to open them.
Bosch superseded the djetronic system with the kjetronic and ljetronic systems for 1974. Approximately up until 1994 mechanical fuel injection systems have been installed on certain mercedes, audi, volkswagen, ford etc. Le is the german designation of the european version of their air flow meter, with lu being the designation of the us version, i. Bosch ljetronic fuel injection troubleshooting, maintenance. It is a socalled hybrid a mixture of mechanical and electronic injection systems. Chapter of djetronic articles by drdjet describes systematic fault finding troubleshooting and repair on your bosch fuel injection system. Someofus rememberthedayswhenwelookedat this systemand thought servicingthis willbeabreezethesystems almost entirely mechanical. The wiring will look a lot different if its from a plain old l jet e12, although it doesnt function much different, the combo vs fuel pump relay and switching for same makes a lot of difference in wires, plus i think peter drew the e12 one, so its appearance would be different even if all the wires were in the same place. Ive taken the time to summarize the information provided in the workshop manual. For the first 30 seconds, up to 60% additional fuel will be provided to. Mercedes suggests that special tools are required to adjust the mixture on the bosch ke3 jetronic cise fuel injection, such as is used on the 198891 560 series motors. What links here related changes upload file special pages permanent link. You should understand this fuel injection system before you begin working.