Originally Posted by Diesel911

You can only do this with the MW Fuel Injection Pump like the one in the picture. I hope no one try this with an M type Fuel Injection Pump; the one that needs the special splined Socket to remove the Delivery Valve Holders.

On your MW Fuel Injection Pump remove the Delivery Valve Holder I believe that is the part you car calling the Pipes as I have seen that word used in the Manual. Do not touch the Nuts on each side of the Pipes.

Remover the Delivery Valve Spring and the 2 piece Delivery Valve. You should be able to look inside and in the center is the Element Plunger.
Have someone rotate the Engine by hand and look inside and see if the Plunger is going up and down.

If it is not moving it is likely that the Plunger is stuck in the upward position.

If the above is the case; I have done this before but it requires that you be extremely careful. You take a 4-6 Inch section of 1/8" OD BRASS Brazing Rod and and get something light weight like a big Spoon.
You round off one end of the Brass Rod. You insert that down the center onto the top of the Plunger and you tap lightly.

If it does not move rotate the Engine about 1/2 a turn and try tapping again. You should reach a position where you can tap the plunger down but it will not move far.

You need to rotate the Engine to rotate the Camshaft in the Fuel Injection Pump so you are not beating on the Plunger when it is being held up by the Fuel Injection Pump Camshaft. That is why you need to tap gently so you do not damage anything.


If the Plunger goes down lube it with WD-40 or Diesel Fuel. If you manage to free the Plunger up you need to bring the Plunger up to the top and inspect it for Brass particles and you need to air gun the particles out.


If the Plunger is not stuck and is moving up and down OK that means the Fuel Feed Hole in the side if the Element is plugged. I guess you will need to find some chemical that can unplug that because if you remove the Element you mess up the Fuel Adjustment on the element.

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Originally Posted by nikkondy

Thanks for the great advice, but I have a few things I want to clarify.
I have attached a picture from the Mercedes manual. When you say to remove the delivery valve holder, spring, and 2 piece valve are you referring to the parts that are in the image. If so how do you remove (6) or pressure valve carrier as they call it. Is it a press fit?

From what I can remember you can rotate the engine by the powersteering pulley instead of the crank if the belt is tight enough. Correct?

Someone else mentioned that it is best to soak it in paint thinner, so I might try to do this to free things up a bit before taping it to make things easier.

Also, is the method you described above possible with the injection pump off the vehicle? Would it be easier to take it off or do it with it still on the vehicle?