The device combines the only petrol injector that comes with the pressure regulator shutter and regulator switch shutter speed idling in a single set, constituting a compact formation of the mixture air- gasoline, which as stated is mounted on the intake manifold of the engine. The injector is installed in the center of the unit forming the mixture, the flow of gas being distributed in the area with the minimum cross-section of the air flow to the cylinders (where air flow rate is the maximum rate). It is done as a homogeneous fuel-air mixture, which is supplied to cylinders in the order they succeed ignition.

The injection pressure upstream of the injector is kept substantially constant by means of the pressure regulator, the excess fuel from the injector is returned by the pressure regulator to the tank.

Adjusting the amount of fuel injected per cycle, for different operating conditions of the engine, is based on the amount of intake air. In this regard, the air flow meter is mounted transducer that transmits information about airflow to the central electronic unit. Other sensors transmit information to correct quantity of fuel injected per cycle transient operation (acceleration, deceleration, enriching the mixture at full load or cold start, etc.). Filled with a lambda probe, Mono-Jetronic equipment is highly efficient in terms of reducing emissions of pollutants.

It is fitted into the exhaust manifold and is able to detect oxygen content in the exhaust gases, which did not participate in combustion. Oxygen signal from the transducer is transmitted to the central command and control unit. Depending on the size signal (proportional to the percentage of oxygen detected) unit changes the volume of petrol injection cycle. It is possible such a rigorous control of fuel consumption and emissions of pollutants produced.

To adjust the idle speed of the controller is provided.

It noted that the adjustment in closed loop using transducer sensitive only in a very limited variation around λ = 1 is only able to meet the effective treatment of flue gases, regardless of the manufacturing tolerances of engines equipped with this facility and those occurring in operation. However, closed-loop control with encoder Lambda cannot act only overlapped a basic control independently fine tuning individual operating in open loop that is added compensation dictated by the change in air density and because of changing parameters injector or engine during operation. Mono-Jetronic system designers have had three major categories of changes that can occur in operation:

• Changes in air density induced alteration (by changing altitude);
• Changes induced by sucking air through holes appeared in operation downstream obturator (false air), additional air shutter considered by the angular position and momentary and partial filling of these holes (e.g. due to “dirt” particles);
• Changes induced weakening of the magnetic parameters that can prolong injection injector.

Subject to those changes, “map features” is subdivided into sectors in which each of the three categories was decisive influences, as follows:

• The change in air density affects the whole area of ​​the folder of features and they will act on “multiplier” airflow;
• Changes in dosage air impoverishment “false” become significant only at speeds close to idling speed and the term is a term calculated nature of addition (not copying).
• Changes from one injection to the next (from one pulse to another) become apparent only at very short injection times, and the correction is all of “additional”.

This open-loop control is known as “adjustment variable mixture” and the principle is to change the duration of injection to obtain dosage stoichiometric whenever finds a deviation from the dosing medium prescribed by intervention of a variable. The variable is corrected by applying a weighting factor specific to a sector of the file characteristics. Variable adopted changes to “distance” operation (which manifests itself in levels of variable amplitude and magnitude of dosage increments superimposed variation imposed by adjusting closed loop lambda probe).

Depending on load and engine speed adjustment steps can take between 100 ms and 1000 ms, so that the effects of tolerances and pollution are imperceptible.