How to replace W203 high pressure injector pump?

[WillElZiBub]

Need to replace the high pressure pump on my W203 C220Cdi 150hp

Can't find a video on YouTube or anywhere on how to do it.

Is it as simple as unbolting the pump from the front, unclipping the electric connection and cutting off the fuel hose metal clips?

If so, I'll do it at home

Someone told me this pump may need timing, is that correct? Or is it just a case of slipping it into its woodruff key, bolting it on and you're done?

Photo of the model of pump below;

 

[Dodipops]

No timing required, just bolt on.

Bear in mind the orientation of the low pressure pipes in to the pump and make sure you secure them back in the clips properly or they can rub on the vee belt.

I would also get new seals for the low pressure pipes.

 

[Supernoodle]

Common rail pumps are timed, even though they will work if you just fit randomly.

First reason is to even out the loading on the crankshaft. Particularly important for belt driven geared pumps where if incorrect it can cause premature belt failure. Not a problem here, but may affect NVH.

The other reason is to ensure the pumping stroke doesn't coincide with the interrupt when rail pressure is read or when you're likely to be injecting. You want to ensure rail pressure during the injection is the same as when read.

 

[WillElZiBub]

Common rail pumps are timed, even though they will work if you just fit randomly.

First reason is to even out the loading on the crankshaft. Particularly important for belt driven geared pumps where if incorrect it can cause premature belt failure. Not a problem here, but may affect NVH.

The other reason is to ensure the pumping stroke doesn't coincide with the interrupt when rail pressure is read or when you're likely to be injecting. You want to ensure rail pressure during the injection is the same as when read.

So how do you time a common rail pump?

 

[mersum1es]

So how do you time a common rail pump?

If its just 'key' slot on head of the axel, you don't. Gear driven pump has intructions in WIS: https://mbworld.org/forums/attachme...pressure-fuel-pump-installation-fuel-pump.pdf

 

[WillElZiBub]

If its just 'key' slot on head of the axel, you don't. Gear driven pump has intructions in WIS: https://mbworld.org/forums/attachme...pressure-fuel-pump-installation-fuel-pump.pdf

It's a woodruff key, it's not timed

 

[Petrol Pete]

From that photo it's not a woodruff key, just a plain slot , (Pedantic Pete , not Petrol Pete , sorry) worst that can happen is it can be fitted 180' out , if that even matters in this application.

 

[Supernoodle]

It should be marked on one side the drive with a dot or arrow. You replace in the same orientation so you are not 180 out. Pump has 3 cylinders, so it's not symmetrical.