TD5 Fuel delivery system presurised?

[wes81]

I replaced my fuel filter yesterday prematurely due to fuel pump screaming during start up (I have also had some very hard cold starting sessions). After replacing it the sound ceased and Disco is running fine so far. However today I got under the RHS Rear of the Disco for another look. I noticed a perished/ cracked hose leading to atmospheric vent pipe ( I think this is correct). Could this allow air to be sucked into the fuel delivery system and have an effect?

[LandyAndy]

Diesel viscosity can vary,especially in cold weather using summer diesel.
What area are you in and has it been exsessively cold for your district????
If you are not in a normaly cold area and it has been it may be the answer.
Andrew

[wes81]

Toowoomba. No it has not been that cold. The reason I think air is due to the noise with the fuel filter and what sounds like gurgling in the fuel lines under the hood. I am certain replacing the fuel filter did something positive, BUT what I really would like to know is 1. whether air can be sucked in at the atmospheric vent pipe/ fuel filling pipe and cause pump pressure issues; 2. is the fuel system completely presurised; and 3. what happens if you don't have a fuel cap.

[justinc]

Wes,

Yes the fuel system has slight tank pressure, and I have run them without a fuel cap to test the one way breather while looking for a fault and they run fine, not advisable though for obvious reasons...

That line shouldn't cause an issue, but I would check that it hasn't got a leaking injector sealing washer, that pressurises the fuel system and can cause hard cold starting and gurgling in the fuel lines while running. It is easier than it sounds to check and rectify this. There is a thread on this in search.


JC