It is necessary to exclude errors during starting. When starting both a cold and a warm engine, the gas pedal should not be pressed, and the clutch pedal, on the contrary, should be pressed.
There should be fuel in the tank, the engine should be mechanically sound, the starter should rotate the engine at the correct speed, the ignition system should be in order, the fuel system should be free of leaks and contamination, the crankcase ventilation system should be in order, the ground connections (engine-gearbox-body) must be reliable, and fault codes must be read from the memory of the unit/control panel.
Caution: Before loosening the fuel lines, they must be cleaned with gasoline or a special cleaner.
[The original entry can be found on the portal «BMWman.ru»]