On going issue, driving me nuts, excuse the pun!

[asauk]

So the fuel senders have been out and replaced, the fuel lines blown through, rubber hose and clips replaced, plastic fuel lines and o rings in the engine bay replaced, new fuel filter, and prefilter.
Yesterday the car has reverted to its old ways of dying at the most inconvenient times.
I'm at a loss what to do, there is still air in the system from somewhere,
There is no sign of a leak in any of the metal fuel lines or tank.

The only odd thing I have noticed is that the tray that I used to catch the fuel from the tank when I changed he senders has an oily yellow liquid in it.
Now I've had he car for over a year and it has had many treatments, and full fuel tanks of diesel. I'm thinking that the previous owner has used strait veg oil, and this is what's left in the bottom of the tank as it doesn't mix with the diesel.

Anyone have any thoughts on what this yellow oily liquid is? The diesel in my fuel container is nothing like that!!
Would veg oil remain in the system for that long?
And any ideas as to how I get rid of it, short of taking the senders out again and physically scooping it out...

Help would be much appreciated.

 

[tonyc280]

Still looks like something is blocking your system.

 

[johnkyte]

Sugar???

 

[grumpyoldgit]

You say that there is still air in the system. Are you sure, or do you think it's the yellow substance blocking the fuel supply somewhere?

 

[sspeed]

asauk..
If you are getting air in then I strongly recommend you change the little O rings that go on the low pressure fuel line from the fuel filter to the High pressure pump..
These O rings get tired over the years and no longer form a perfect seal..
Its not so much that they leak as allow air to be drawn in as the engine cools down.
The photos below are of my C270Cdi engine but its the same principal and shows what to look for..
My car got very hard to start from cold...
1st photo = High pressure pump O rings.
2nd Photo = shows location of rear seals, which I replaced even though they weren't leaking.
3rd Photo shows close up of what to look for at the high pressure pump. You will note its damp..
Its the most common for the front O rings to go because they go through thousands of Very hot / Cold cycles. The rear seals don't get anything like as hot.

 

[clanny]

The veg oil would mix with the diesel and so it wouldn't hang around that long.

A yellow liquid sounds odd but I have seen yellow wax appearing as olefins evaporate but I'd be surprised if that was the case. Could it be? Have you given it time to evaporate? Diesel isn't naturally clear, it has a tinge of colour, and that's extra low suphur diesel but I can't see it being that even if you use "regular diesel" with higher sulphur content.

I'm sorry I can't come up with an answer to your problem though.