L3-JETRONIC
Specific systems for specific markets have in the meantime been developed on the basis of the L-Jetronic. These systems include the LE-Jetronic without lambda closed-loop control for Europe and the LU-Jetronic system with lambda closed-loop control for countries with strict exhaust gas emission legislation. The most recent stage of developement is the L3-Jetronic which differs from its predecessors.

LAMBDA
Eleventh letter of the Greek alphabet, used in some countries to express the ratio between the air quantity actually used and that is theoretically necessary to make the air-fuel mixture to feed to the engine.

LAMBDA CLOSED-LOOP CONTROL
The lambds sensor supplies a signal which represents the instantaneous mixture composition. In the control unit, the signal of hte lambds sensor is compared with an ideal value, thus controllin a two-position controller. Dependent upon the result of comparsion, either an excessively lean air-fuel mixture is enriches or an excessively rich mixture is leaned. Fuel metering is influenced via the opening time of the injection valves.

LAMBDA CLOSED-LOOP CONTROL CRCUIT
Deviations from the stoichiometer air-fuel ratio are detected and corrected with the aid of the lambda oxygen sensor. The control principle is based on the Lambda sensor measuring the level of residual oxygen in the exhaust gas. This residual oxygen is a measure for the composition of the air-fuel mixture supplied to the engine. The Lambda sensor is installed so that it extends into the exhaust gas and acts as a probe which delivers information as to whether the mixture is richer or leaner than lambda=1.

LAMBDA CLOSED-LOOP CONTROL TESTER
ON L-Jetronic systems with Lambda closed-loop control, this tester serves to check the integrator voltage, the lambda sensor signal, and the "open-loop/ closed-loop control" function. Special adapter lines are available for connection to the Lambda-sensor cable of the various vehicle models. Measured values are shown on an analog display.

LAMBDA OXYGEN SENSOR
The oxygen sensor is a "dual-thresgold" unit capable of indicating both rich and lean mixtures. The radical transitions that characterize this sensor's response curve facilitate mixture adjustment to achieve lambda=1

LAMBDA PROGRAM MAP
The Lambda map is used for recise adaptation of the air-fuel ratio at all static operating points once the engine is warm. This map is stored electronically in the digital cicuit section of the ECU; the reference data are determined empirically through tests on the engine dynamometer.

LAMBDA SHIFT
Because the sensor's response pattern varies depending upon the direction of the monitored mixture transition, a symmetrical control arrangement would produce the slightly lean exhaust mixture. Because catalytic converter efficiency is optimal in the lambda=0.99...1.0 range, the control systeem must be able to counteract this tendency. An asymmetrical controller oscillation pattern can shift the mixture into the optimal conversion range.

LEADED GASOLINE
Environmental considerations dictate the leaded fuels be used exclusively in those engines with exhaust valves that require the combustion products of lead-alkyl compounds for lubrication. This basically applies only to a small number of older vehicles, and sales of leaded gasoline are decreasing steadily.

LEAN BURN
This definition applies to engines whose cylinders can be fed much leaner air/fuel mixtures than those used in traditional engines.

LEAN-BURN CONCEPTS
Pollutant reduction based on the catalytic converter is an "external process" without any direct influence on the engine's internal combustion processs. Yet another startegy relies on modifying "internal processes" by focusing on such factors as combustion-chamber design, valve timing, exhaust-gas recirculation, compression ratio, ignition timing and air/fuel ratios.

LEAN MIXTURE
The designation l (lambda) has been selected to identify the excess-air factor used to qantify the spread between the actual current mass A/F ratio and the theoretical optimum (14.7:1).

LH-JETRONIC
The LH-Jetronic is closely related to the L-Jetronic. The difference lies in the hot-wire air-mass meter which measures the air mass inducted by the engine. The result of measurement is thus independent of the air density which is itself dependent upon temperature and pressure.

L-JETRONIC
The L-Jetronic is an electronically controlled fuel-injection system which injects fuel intermittently any form of drive. It combines the advantages of direct air-flow sensing and the special capabilities afforded by electronics.