Yesterday it was on test drive with a 525i type E28 from 1984. After about 45km I noticed that it was no longer perfect in the lower gears. Since I suspected the tank watch to display too much, I refuelled 25 liters, but it didn’t get better. The engine accepted less and less the gas request until I got ahead only with a little more than the idle speed. In the stand one could speed up the engine, at the gas lever high, but as soon as one wanted to drive away, nothing went again. The vehicle was reactivated after 15 years of standstill, the tank emptied and a new fuel pump with filters installed. Either it solved something in the tank, which clogs the fuel line or there is another fault in the fuel system, the question is only which one?