Air in fuel system

[Dunx]

Had problems starting again this morning. I replaced all the clear fuel hoses (they come with new o-rings fitted) last week. There appears to be fuel leaking from the back of the shut-off valve somewhere, but it's very hard to pinpoint as the intake manifold obscures access. Does anyone have any experience with the shut-off valve on the 606.962 engine? I'm going to try replacing the o-ring seal between it and the injection pump tomorrow and see if that helps. A new valve is £100 from the dealer.

Time to take the inlet manifold off again!!

TIA

Duncan

 

[Oilysump]

Definatly change the 'O' rings first ,before shelling out £100 for a new valve(as I did).The valve comes off very easily,it's just held on with 2 hex bolts(can't remember the size).I didn't take the inlet manifold of to do it though,seem to remember removing the windscreen washer bottle,a little fiddley but beats removing the manifold.Hope this helps.

 

[pcman_jh]

I had a 605 engine (from a 1994 C250D). Changed every O ring there was and still had problems. Turned out to be the rubber fuel bleed pipes that run from injector to injector. Although they looked visually OK, two of them crumbled in my fingers when replacing them. The bit that crumbled were the ends that push fit onto the injectors. Never had a bit of bother since (up to hte point I sold it).

Regards

 

[Dunx]

Thanks for the tips guys.

I already changed all the leak-off hoses that run back from the injectors as one was leaking. Nice puddle of diesel in the injector recess!

To be honest, once you've done the inlet manifold once, it's not that daunting. Hopefully it's the o-ring, but i'm not convinced!

I'll keep you posted.

Dunx

 

[Dunx]

The problem was a flat o-ring on the shut-off valve where it mated with the suction gallery on the injection pump. I replaced the o-ring yesterday (manifold off, etc!) and all is now well.

I'm hoping this will also do something for my fuel consumption too. 23mpg prior to replacing the clear fuel lines and fuel filters.

Thanks again,

Dunx

 

[television]

If fuel comes out, air goes in, the reason that starting becomes hard is that air can be compressed and fuel cannot, so it takes a lot of cranking to get sufficient preasure to open the injectors

malcolm

 

[Dunx]

Yeah, it must have been leaking pretty badly as there was diesel everywhere.

The trick is also to remember to fill the fuel filter before attempting to start or all that air goes nowhere (as you say it compresses and cannot open the injectors).