The flowtronic pressure regulator with manometer FLO-4801 is used, if the vehicle fuel pump is located directly at the fuel tank. The vehicle’s fuel pump pumps the fuel from the tank to the engine. The engine is equipped with a pressure regulator, which reduces the fuel pressure into a range of 2 bar to 4 bar. The pressure regulator directs the excess fuel from the engine back to the fuel tank. This fuel system is common for petrol engines (L-Jetronic, E-Jetronic, Single-Point and Multi-Point injection systems).

K-Jetronic injection systems require the use of the flowtronic-heat exchanger (e.g. 4703X). The use of the pressure regulator has not been proven with the K-Jetronic injection system.

The original fuel circuit uses the engine’s pressure regulator to direct the excess fuel from the engine back to the tank. Inserting the sensor just in the feed flow will lead to fake measurement results, as the return flow will be measured in the same way. It is required to modify the original fuel circuit in that way, that the return fuel flow is stopped and that the sensor measures only the feed flow volume, which is consumed by the engine.

The pressure regulator set FLO-4801 allows to modify the original fuel circuit, as it introduces an additional pressure regulator. This additional pressure regulator takes over the function of the engine’s pressure regulator. The return fuel flow from the engine is stopped and the sensor will measure exactly only the feed flow volume consumed by the engine.

The original engine’s pressure regulator stays with the vehicle, but is obsolete due to the additional pressure regulator. The excess fuel is directed to the tank from the additional pressure regulator.

The use with a heat exchanger of type flowtronic 4703X is not common, but possible.
A heat exchanger unit (e.g. 4703X) is necessary for fuel consumption measurement, if it is technically not possible to stop the return flow from the engine as described above with the pressure regulator set.

The heat exchanger unit allows to set up a fuel circuit at the side of the engine with an additional heat exchanger. The heat exchanger uses the vehicle’s fuel pump, the feed flow and the return flow of the tank to operate the heat exchanger.

The pressure regulator set is required as accessories for the heat exchanger unit, if the feed flow pressure needs to be reduced.

The integrated fuel pump of the heat exchanger represents the fuel pump for the engine. It may be, that the engine’s injection system is overloaded and that the engine refuses to run, when the integrated fuel pump provides full fuel pressure and full fuel rate. The pressure regulator can be added to the heat exchanger and will reduce the fuel pressure for the engine’s injection system.Further information regarding the heat exchanger unit is available in the respective technical data sheet.

The pressure regulator set is used to modify the original fuel circuit to install the flowtronic sensor and consists of:

1. Connection (green/yellow) for the return flow from the engine. The excess fuel flows back from the engine via connection 2 to the tank (please see 2)
2. Connection (blue) for the return flow to the tank. The connection is needed to purge (to air) the tubes after installation (please see 8)
3. Connection (red) for the feed flow to the engine (via the flowtronic-sensor)
4. Sub pressure connection, used with Multi-Point injection systems
5. Connection (red) for the feed flow from the tank
6. Pressure regulator
7. Set screw to adjust the fuel pressure for the engine’s injection system
8. The set screw is part of the pressure regulator 6
9. Three way valve to set the fuel circuit before the measurement (purge procedure) and during the measurement

The pressure regulator requires the use of the manometer. The manometer belongs to the scope of supply of the pressure regulator set FLO-4801. The manometer is used to read and to set the vehicle’s specific feed fuel pressure.
    

Vehicle specific connection sets and the universal connection set are used to adapt the tubes of the measurement equipment to the vehicles fuel tubes. Vehicle specific connection sets are offered on request.