Rough / smokey OM606

[Sgt-Slow]

Has anyone got the part number for an British W124 300D (naturally aspirated) mechanical fuel lift pump?

Engine is OM606

Feels sluggish, intermittently smokey, occasionally diesel knock (at indicated 80°c). New fuel filter and pre filter, no obvious leaks or air leaks.

I guess fuel lift pump is a good place to start now?

 

[bembo449]

Have you done a spill test on injectors yet ??

 

[Sgt-Slow]

Not yet. How do I do that? Is there a guide online?

 

[bembo449]

You need to rule out injectors pal so get it done asap , its easy enough , google is your friend

 

[Doug1234]

The fuel tank strainer can also cause this problem in fact its notorious for it
The fact you mention it is intermittent smoke points to fuel starvation.
On the om603 engined w124’s you could swap fuel lines around under bonnet where they joined the metal lines that run under the car to get around the problem until it could be fixed... not sure if the om606 engine will have different size fuel hoses though like the om606 turbo model does 8mm and 10mm internal bore

 

[Sgt-Slow]

Where would the fuel tank strainer be accessed from? Can you get access from the top, by removing the rear seats?

 

[Doug1234]

If its a saloon its from underneath the car , estate im not sure.
But look through this link for info on removing.
http://www.peachparts.com/shopforum/diy-links-parts-category/142399-diesel-fuel-delivery.html
If its a saloon you can loosen tank and lift it up each end on a couple of inches of wood and unscrew the strainer from inside car with a large adjustable spanner.
On my old w124 I had tank off and cleaned it out and then just took the strainers mesh off and replaced it.
If its covered in gunge then get some Startron Starbrite and add to fuel as it kills diesel bug and algae.... other brands do the same but this one dissolves it all and it can pass through filters and be burnt with fuel whereas the other brands kill it but not dissolve so it gets caught in filters.
It may not be the problem but 90% of the time it is.
But try swapping fuel lines over first because if it runs ok after that then you know its the strainer and a bottle of Starton over a month of driving should see it all off.