The Diesel adapter set FLO-5711 is used at vehicles with their fuel pump directly located at the engine.

The original fuel circuit directs the excess fuel from the engine back to the fuel tank. This leads to a wrong measurement, if the return flow is not stopped. This can be achieved with a modification.

The Diesel adapter set FLO-5711 allows to introduce the modification to the vehicle’s original fuel circuit. The return flow will be fed directly back to the engine. The excess fuel stays in the engine circuit and can not be measured again from the sensor. Additional fuel is sucked from the engine’s fuel pump from the tank via the sensor. The sensor measures the volume of the additional required fuel volume, which represents the fuel consumed by the engine.

Usually it is sufficient to work with the Diesel adapter set . The use of the heat exchanger (e.g. 4703X) is required, if the measurement set-up with the Diesel adapter set does not work

The Diesel adapter set allows to execute the required modification to the vehicle’s fuel circuit and consists of:

1. Connection (blue) for the return flow to the tank. It is used to purge the measurement set up after installation (please see 5).
2. Connection (green/yellow) for the return flow from the engine. The excess fuel flows from the engine back via 3 into the feed flow to the engine (please see 3).
3. Connection (yellow) for the feed flow to the engine. The feed flow is the excess fuel from the engine (return flow from the engine, see 2) and the feed flow from the tank, which is measured by the sensor (please see
4. Connection (yellow) for the fuel hose of the flowtronic sensor. This tube provides the new feed fuel, which is sucked from the tank via the flowtronic sensor.
5. Three way valve to set the “Purge” and the “Normal” position to be able to air the hoses after installation (to purge) and to set the modified fuel circuit for the measurement (to normal operation).

The measurement configuration of the fuel circuit directs the excess fuel directly back to the engine. Only the feed flow volume from the tank is measured, which is the fuel volume consumed by the engine.

The three way valve has the two distinct working positions “Purge” and “Normal”.

• The position “Purge” connects the return flow from the engine (2) with the return flow to the tank (1). Air in the hoses is pushed to the tank after installation.
• The position “Normal” closes the return flow to the tank. This is the position for the normal measurement after the successful purge procedure.
• The positions between “Purge” and “Normal” are not used!

• A vehicle specific connection set or the universal connection set are used to install the tube connections. A vehicle specific connection set can be offered on request.

• It may be necessary to cool down the hot fuel from the engine. The return flow cooling coil FLO-5791 is the first choice.

It may be necessary to use a heat exchanger unit (e.g.4703X) due to the engine not working properly, when the excess fuel is directed back to the engine as feed flow.

The heat exchanger unit installs an engine circuit, which has the hot return fuel from the engine cooled down before fed as feed flow back to the engine. The cooling power is much better as just using the cooling spiral. The cooling performance is created with the fuel pump of the heat exchanger unit, which sucks the fuel from the tank, presses it through the heat exchanger and back to the tank.

Further information regarding the heat exchanger unit is available in the respective technical data sheet.