Caution! Risk of malfunction due to contamination. To avoid dry running of the high-pressure fuel pump (very tight tolerances) and in order to quickly start the engine after replacing parts, the following points must be observed. When removing or replacing parts/components of the fuel system, the first filling of the fuel system must be carried out between the fuel tank and the high-pressure fuel pump. After removing or replacing the fuel pump, fuel line (between tank and high pressure fuel pump) or fuel filter, it is necessary to bleed the fuel system before the first start of the engine. After removing or replacing the high-pressure fuel pump, it is necessary to bleed the fuel system before the first start of the engine. Failure to perform the first refueling will damage the fuel pump.
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Fuel system parts and components (general scheme). I 1. Fuel tank: with fuel booster pump "G6"; 2. Fuel filter; 3. Not installed; 4. Mesh filter; 5. Fuel temperature sensor "G81"; 6. High pressure pump: After replacing the high pressure pump or the fuel pressure regulating valve "N₂76", it is necessary to carry out a new adaptation using a tester; 7. Fuel metering valve "N₂90": do not open; 8. Fuel pressure regulating valve "N₂76"; 9. Fuel distributor; 10. Fuel pressure sensor "G247"; 11. Throttle; 12. Nozzle
[Material republished from the website «AudiManual.ru»]