CDI fuel pump at fault maybe?

[CHEWIE]

Hi, have previous posts regarding E320 cdi fuel lines that I have replaced and now cannot bleed system, wondered if maybe the pump at fault?
wondered if anyone knows if I can check/eliminate pump?
Be gratefull of any help as pulling my hair out now!...lol.
Cheers.

 

[Xtractorfan]

Have u checked that you have routed the fuel lines properly..there are two pumps at the front of the engine..If u slacken one of the injector pipes slightly and crank the engine the fuel should squirt out.. so be careful cos it can be dangerous .getting an eyeful of fuel

 

[Xtractorfan]

also did you by any chance replace the fuel filter

 

[CHEWIE]

Hi, not replaced filter as recentlly replaced at service, and yes lines routed as originals, but now wondering if another prob as remembered that on first try after changing the lines the ECP warning came up on display, but went away again, so assumed ok!...maybe not? .....any ideas anybody? and should I have replaced the filter? only been in for about 2000 miles.
Thanks again.

 

[Xtractorfan]

without actually checking i think that ecp warning is to do with the fuel pressure in the fuel rail.. there should be an electrical connection at each end of it and a fuel pressure valve, I will check this for you in the morning. the reason for asking about the fuel filter is sometimes the seal isnt fitted properly alowing air into the system and fuel to escape

 

[CHEWIE]

Ok, Thanks for that, i would hope its the correct filter, as replaced on service at authorised service centre.
When you mention the seal on fuel filter, do you mean the housing or top of filter itself?
Also is it possible that the filter housing is at fault/leaking?.....no obvious signs.

 

[CHEWIE]

Ok, Thanks for that, i would hope its the correct filter, as replaced on service at authorised service centre.
When you mention the seal on fuel filter, do you mean the housing or top of filter itself?
Also is it possible that the filter housing is at fault/leaking?.....no obvious signs.
look forward to your reply tomorrow.

 

[CHEWIE]

Just been thinking about it and wondered if the clear fuel pipe that connects to back of rail is a feed or return as there is a metal pipe connected to rail from pump too, so should I see this fill prior to starting? or once rail is filled and then returns through clear pipe?... also what is the purpose of the plastic valve at the end of clear pipe on top of engine please?...thought I would update on progress..can now start engine but will only run for 2-3 seconds and stalls again, no malfunction messeges,could it be an immobilser issue after low battery? Ive heard this acts on fuel pump, and how could i check this/reset? Thanks Again.

 

[mister_cee333]

I'll throw something else in here for "food for thought".

Why did you replace the fuel lines in the first place? The 2150cc cdi engines are prone to injector faults which give poor starting and air bubbles in the return pipes. Perhaps the 320 has a similar set-up and your problem lies there?

 

[CHEWIE]

possibly, as stated in previous posts, it was difficult to start but would run fine after easy start, so advised to replace o rings, but as fuel lines ols and brittle (200k), decided to replace whole lines, have disconected leak offs from injectors, but none giving exesive diesel delivery, which im told is a sign, any ideas how I can elimate them completly?. Cheers.

 

[mister_cee333]

AFAIK the injector test is a leak off test, as you say. The one returning too much diesel is faulty. If you're not familiar with how much should leak off then is it remotely feasible (but improbable) that they're all faulty??

Sorry I know thats not much help.