320cdi bleeding fuel system

[CHEWIE]

Hi, wondered if anyone could give me details of how to bleed the system, have just replaced clears fuel lines and now cannot bleed , not sure if doing properly,but have followed other instructions but to no avail.(see my previous posts) Thanks in advance.

 

[panason1c]

As previously mentioned, the normal method to bleed the fuel system is to just keep cranking the engine over, when i replaced my fuel filter it took an awful lot of cranking before the engine fired up.....i think the handbook also instructs you to do this in the case of running out of diesel.
Sounds to me that there is a problem somewhere where air is being drawn in.

 

[type49]

Depends what it is. Some cars have an electric pre pump, depending on what year. What is it???

 

[CHEWIE]

Yes have tried cranking in for a couple of hours in total (with resting engine between) as had to recharge battery, but the fuel drops back!, would this indicate air still getting in?
It is a 2001 (51), Thanks.

 

[type49]

2001 won't have the electric pre pump. It relies 100% on a mechanical pump on the front of the engine. Have you got the two clear pipes on the pump the right way round. Also try cracking off the 14mm injector pipes at the injector ends. When these start to spray fuel, retighten & then try again.

 

[panason1c]

did the car run before you did any work on it?.........if the answer is 'yes' then you need to double-check everything you've touched.....air is definately being drawn in somewhere.

 

[luders79]

Hello
I'm sorry if i've missed it but what model car have you got ?

Lee

 

[CHEWIE]

Hi luders, thanks for your interest, vehicle is a 51 e320cdi. Cheers

 

[luders79]

When you crank over the car do you get any fuel up the clear plastic pipes that are on the front of the engine? The system has two pump on the front of the cylinder head the small one which I think is at the top is your suction pump this draws fuel up from the tank then supplies it to the high pressure cdi pump which is bigger and just below the suction pump! You can tell it as it will have a metal pipe on it which connects to the main fuel rail ! Check that you can got fuel running through the plastic pipes! I might be wrong ? (some please correct me if I am) The suction pump has got arrows on it for follow direction I think! check you have got the pipes on the correct way round i.e fuel in to pump should be coming from the pipe off the top of the fuel filter!

Am assuming that the car was running before you done the work !
If yes then double check everything again just as PANASON1C has already said!

If thats all o.k then I would suggest that you remove the leak off pipe from all injectors and crank engine over you are looking for one of the injectors leaking more fuel out than any of the others! If there is one leaking off more then that will give you a non- start issue aswell!

Hope some of this maybe of some help!!

Lee

 

[CHEWIE]

Cheers Lee,
Have double checked and tripple checked too! have tried pipe connections in other ports on lower side of pump, (in case i messed up!), have cracked injector nuts, have even tried PTFE tape on seals and tried to backfill pipe to common rail to aid bleeding....., the pipe layout is short pipe from top of filter to lower port on top section of pump, above that (heading downwards) you have another port this pipe has a T peice branch in it, one pipe leads to the plastic valve thingy at top of engine other goes down under pump and goes into one of two ports at left base of pump, being the one closest to the block and the other port nearest the fan has the pipe which leads directly to rear of rail, and yes marked with arrows showing fuel in (from filter) on lower and out on upper ports of pump.
fuel travels partilay up pipe with valve thingy, but drops back and doesnt travel up pipe to rail at all, that I can see.
If you read my previous posts there is more detail but needed easy start towards end before replacing pipes, would always start and run superb, so Im really baffled now!...been told by other member that pump should not be an issue,...but begining to wonder!!??...any ideas anyone?

 

[IAN MAC]

When you replaced the filter, did you also change the the little 'o' rings on the fuel lines. ?? May be an issue here for drawing air, i've been supplied the wrong size in the past and it wouldn't start. !!!

 

[CHEWIE]

I didnt change filter as this was done at recent service,should I have? have just replaced fuel lines with o rings attached, all connections seem good, no obvious leaks, I know you cant always see leaks, but dont know what else to check now!, would you know if it may be the pump at fault,or maybe new fuel ines? if you read my previous posts you will get a better idea of problem.Thanks,Ray.