To check the cause of the starting difficulties, i.e. to check whether fuel is supplied to the injectors, loosen the union nuts on the two injectors and start the engine without preheating until fuel comes out from under the nuts. Tighten the union nuts to 20 Nm and start the engine in the usual way.
Note: If the system is not automatically purged of air, the following steps must be taken.
When working, cleanliness and safety regulations must be observed.
Make sure that diesel fuel does not come into contact with the cooling system hoses. If this does happen, clean the hoses immediately. If the hoses are damaged, they should be replaced.
Remove the fuel line going to the high-pressure fuel pump from the fuel filter, for which press the clamps. Collect the leaked fuel.
Insert a suitable hose into the connection thread and direct it into the vessel.
Remove the fuel pump relay and jumper the contacts in the relay socket to allow the fuel pump to supply fuel.
When fuel comes out of the connection, remove the jumper and insert the relay.
Install the fuel line, having previously lubricated the gaskets with technical petroleum jelly or acid-free grease. Replace damaged gaskets.
Loosen the plug bolt (1) on the high-pressure fuel pump by two turns.
Turn the engine over with the starter until fuel comes out from under the plug bolt. Collect the leaking fuel.
Tighten the plug bolt (1) to 25 Nm.
After unscrewing the bolts, remove the covers from the intake manifold.
Loosen all union nuts on the injectors using a special tool on the high-pressure fuel lines. Turn the engine over with the starter until fuel starts to flow out. Then tighten the nuts to 20 Nm. If there are any leaks, tighten the nuts to 25 Nm.
Carefully collect any leaked fuel in the engine compartment.
Install the engine covers.
Original publication posted on the website «BMWMAN»