C5 2.2 HDi doesn't start after changing the fuel filter housing

[ghumu]

Hello everybody,

I have recently had a major fuel leaking problem with my C5 Mk1. It leaked from the sealing of the fuel filter housing (which was 6 months old), and one of the fuel hoses. I have decided to replace it myself, as it seemed quite easy to do, so I’ve ordered a completely new housing and replaced it a few days later.


The car won’t start now. I have tried adding fuel to the housing before starting, removing it and letting the car pump the fuel into the filter. It didn’t help.

Then I’ve searched for help from a mechanic. He replaced one of the hoses and started the car. When I came to collect it, it started fine, and I thought that it was finally fully working. It worked until I stopped the engine. It wouldn’t start again. After I called him, he said that I should unplug one of the fuel hoses to depressurise the fuel pump and it will start. So, I had to do it every time I wanted to start the car. 
That method worked the next 3 times I needed to start the car, and once I’ve even travelled about 100km without turning it off without having any issues with it.
Here’s a video I’ve made yesterday:



It is after I’ve disconnected the fuel hose, depressurised the pump (let the fuel leak into a plastic bottle) and tried starting it up. It almost started the first time (like the other 10 times I’ve tried since the last time it stopped) and it just didn’t have the energy to start the second time.
That's exactly what happens every time I try turning it on:
- when depressurised: turns (almost) on and stays active for a few seconds
- the next time: it just won't start

Does anybody have any clue what could be the issue? Is there anything I could try doing to discover the problem?
could it be that the fuel leakage caused some additional issues with some other components? is there too much air inside the engine or some fuel hoses?

Thank you all in advance!

[GiveMeABreak]

Hi and welcome.

Are you sure you undid the bleed screw by one turn on the fuel filter housing? Then try to start once, then leave it and wait a few seconds, then start it again. If it starts, let it run for a minute, then stop it and tighten the bleed screw.

See this post also:

viewtopic.php?t=46149

[ghumu]

See this post also:
viewtopic.php?t=46149

I actually wanted to try that method, but my version of c5 doesn't have that ball which the other users were squeezing.

I have completely tightened the screw on the filter housing before mounting it. Is the fuel going to leak when I undo it by one turn? I am going to try that in a few hours when I get back to the car (I left it 10km away from home, as it wouldn't start). Do I need to do anything else with the pipes while the screw is undone by one turn?

Thank you for a fast reply!

[myglaren]

Yours will have the in-tank fuel pump to feed the HP pump.

Try checking the fuel return line. If this is blocked it may be responsible for overpressurising the HP pump prior to starting the engine.

[GiveMeABreak]

I have completely tightened the screw on the filter housing before mounting it. Is the fuel going to leak when I undo it by one turn? I am going to try that in a few hours when I get back to the car (I left it 10km away from home, as it wouldn't start). Do I need to do anything else with the pipes while the screw is undone by one turn?
Thank you for a fast reply!

Ok, so for your engine, they recommend using a tool to bleed the system - which is highlighted in yellow in the diagram - and instructions follow:

Couple the female union (10 mm) of the tool [7] in place of the pipe (3), as "e". Disconnect the fuel return pipe ( 9) and insert the union (Ø8 mm) of the tool [7] into the fuel return circuit. Switch the engine on and off 10 times in order to fill and bleed the fuel filter. Remove: The tool [7] The tool [6] from the pipe (3) Couple up pipes ( 3) and (9). Switch the engine on and off 2 times

[ghumu]

Ok, so for your engine, they recommend using a tool to bleed the system - which is highlighted in yellow in the diagram - and instructions follow:

I don't quite understand the image... I already have all those pipes and the three-way separator - "the tool" (it can be seen at the beginning of the video I've posted). I just need to reconnect them in a specific order, switch the engine on and off 10 times to bleed the filter and reconnect them the way they were connected before the procedure?
Is there any additional photo which describes which pipe is which (they are numbered under the image, but not marked on it)?

Should I fist try the last method of opening the bleeding screw and turning the engine on?

Sorry for all the questions, but I'm still a newbie.

Than you for your time and effort!

[GiveMeABreak]

So basically once you've disconnected the pipes, opened the bleed valve and removed the fuel filter to clean or replace, fitting is a reverse - and bleeding is using the tool as described. I've included another diagram to show the pipe (3) that they are referring to at 'e' in the third diagram.