C250td (OM605) Air in fuel ! Changed plastic pipes

[Charlie 250td]

Hi,

Recently ive been having running issues with the old girl she starts on the button runs all day long but as soon as you put your foot down she simply shuts down to a lumpy idle...

As ive said ive replace all fuel lines ! Now..... the air is bubbling from the injector pump overflow pipe (the one with the banjo bolt through it) its very tight on there and ive change the copper washers and even put black sealant round the joints !

So, I have just been told (mercedes Cambridge) it could be the injector pump shut off valve seals ? could this be right ? Im sure this part of the system is "under pressure" meaning i would have a fuel leak rarther than drawing in air ?

Please help a fellow owner out ! ive had it apart 4 times in a week trying to solve this problem.

Thanks in advance

 

[turbopete]

have you changed the rubber 'o' ring between the shut off valve and the engine block? they are known for allowing air into the fuel system

 

[Charlie 250td]

Hi Pete,

Thanks for the reply, ive got them coming in the morning ! The problem is the bubbles are coming from the return side of the pump ! (banjo bolt leak off / overflow valve).... Would this not be the pressure side of the system ?

Also..... its the shut off valve linked to this ? would the cause air the leak to the overflow pipe

Thanks

 

[turbopete]

do you have a picture of the area in question? if the leak is on the return side, its possible that air is coming in through the braided leak off pipes. they are cheap to replace, and replace the end blanking plug too.

really speaking air in the return feed shouldnt affect running unless its going back into the filter and then filling the pressure side of things with air!

 

[Charlie 250td]

http://mb.autokit.com.ua/1/car/210.610/45Q/605.912/19S/07/120/p/1

This is the link to the image (number 128) ! Thanks i hope you can help ive spent almost a week trying to get the dam thing to run !

 

[Charlie 250td]

One other question is the Shut off valve linked to the overflow ?

 

[dieselman]

One other question is the Shut off valve linked to the overflow ?

No it's not, but due to fuel flow it's possible that air could be drawn in even with the fuel under pressure, but also check the fuel delivery rate is sufficient.
A blocked feed pipe or lazy lift pump could cause fuel starvation under high load.

 

[turbopete]

looking at that diagram, the item no 125 is a pressure relief valve for the injector pump. IIRC these can fail causing poor starting.

 

[Charlie 250td]

Ok just got back from mercedes cambs ! ive got the the shut off valve seals ect ! ill let you know how it turns out !

Ps its NOT a starting issue it starts and runs fine, it draws air in under load and heavy throttle !

very very odd if i can sort it ill let you know !

Dieselman - Surly if the lift pump is supplying fuel this would not be the issue ? or is it that its unable to keep up with deman under load ?

Thanks Guys

 

[turbopete]

it could be a partially blocked tank strainer, if theyre fitted to the 202

 

[Charlie 250td]

Hi Pete,

No they do not have them according to mercedes ! i hope there right :neutral:

They just have the pre filter in the side of the housing ...

.., Cant stop for long just on a tea break better get back to the beast and get craking, by the way it looks as if the o ring on the shut of valve could be the problem as it jest fell off the outlet plus its look quite square !


i just hope this is all and it will run and drive as good if not better than i did !


Fingers crossed and thank you for your help

ill keep you posted

 

[Charlie 250td]

thanks for all your help shes running a dream now ive on been up the road and back a few time but so far so good !

Thanks again

 

[Thomas Lorenz]

Hello, I have a 1994 C250d. I need to replace the hard plastic fuel lines. I can't see the part numbers on the installed pipes and don't want to remove the pipes in case they crack. Can anyone help me out with either individual part numbers or a part number for all the pipes (kit). Any pointers would be greatly appreciated!!

 

[Doug1234]

I do not know the part numbers but if it helps I purchased all the clear plastic pipes on my 97 w210 e300td last year and total cost from Mercedes was £67. All the pipes come ready to fit with the o rings installed on them.
You could buy a viton o ring seal kit for the pipes from ebay for under £20 and take a chance on pipes breaking. In my experience if you pull on them evenly they come off ok.