Phaeton without rail pressure after HPFP replacement

[SaVAGeSoot]

Does this model\engine also use an AUX pump between the fuel filter and HPFP?

I just looked it up and answered my own question.....

8.3 Assembly overview - supplementary fuel pump - V393- , engine codes CARA,CEXA, CEXB Note The supplementary fuel pump - V393- is installed on the side of the fuel filter in the engine compartment

So, have you confirmed this is working? Are you making sure you're activating both pumps when priming the system with VCDS?

 

[Mknsweden]

Yes LPFP is working (we did do the bleeding with it) and we verified that it is pushing fuel. We have also run the AUX pump via VCDS and that is moving fuel as well. I also removed the pressure sensor to check it (not while cranking) and there was a substantial pressure release with diesel when loosening it. That why im so suspicious of the 0 BAR reading in VCDS.

 

[SaVAGeSoot]

You need to reference the FSM and make sure your LPFP & AUX pumps are creating the required pressure and flowing the correct volume of fuel.

 

[Mknsweden]

I just looked it up and answered my own question.....

8.3 Assembly overview - supplementary fuel pump - V393- , engine codes CARA,CEXA, CEXB Note The supplementary fuel pump - V393- is installed on the side of the fuel filter in the engine compartment

So, have you confirmed this is working? Are you making sure you're activating both pumps when priming the system with VCDS?

In VCDS I can run both pumps in testing. The bleeding was done with a VW shop computer with a friend who is a VW tech.

 

[SaVAGeSoot]

The bleeding was done with a VW shop computer with a friend who is a VW tech.

OMG.... so a VW tech with ODIS and the vehicle physically present can't figure out why this isn't starting, and you somehow expect us to guess here at what's wrong, across the internet?

 

[Mknsweden]

OMG.... so a VW tech with ODIS and the vehicle physically present can't figure out why this isn't starting, and you somehow expect us to guess here at what's wrong, across the internet?

Wow. Jumping to conclusions. Yes, with small children and living far away, im kind of glad that he was able to spend an hour and a half to help us out with the first most possible issue.

So yeah, I turn to the most reliable forum I know of. Thinking that a couple of 100 / 1000's of VAG specialists would be a faster solution than one guy with his ass completely full. If I had him locked up in my basement I probably wouldt be here.


So yeah. Sorry for the rude post, I do appreciate your help. But is there any harm in seeking advice from multiple sorces?

 

[Vdub]

is the turbo still good? not that its not turning and blocking the airway? Airfilter? Or clogged DPF?

 

[SaVAGeSoot]

How would an air restriction keep the HPFP from making pressure?

 

[Vdub]

without air it doesnt start

 

[SaVAGeSoot]

without air it doesnt start

Also the HPFP pressure now reads 0 BAR.

You can have all the air you want and it still won't start without fuel.

 

[Mknsweden]

You can have all the air you want and it still won't start without fuel.

Yeah Turbo is good. Airfilter is new (also tried to start it with filter and air intake removed). No prior issue with DPF before the HPFP going into a million pieces. It really was a catastrophic faliure of the HPFP, evident by the million pieces of metal in the old HPFP.

The main issue as I see it is that there is not any / enough pressure for it to start. Then if it is a sensor issue or mechnical issue of injectors etc is the million dollar question. To me it seems quite odd that the reading in VCDS now is 0, but when removing anything on the high pressure loop there is deffinetly pressure. Like safety goggles amount.

 

[stefdds]

Perhaps you should at least remove the injectors and send them to someone for cleaning and analysis.

Post #16 and 17 seem to be quite conclusive.

 

[Rossatron]

Here is an update and response to all great answers! Thanks to you all!

Yes, we do have a crank signal and rpm at crank is a bit above 250 rpm.

Im well aware of the glitter and shards contaminating the complete system. However, since this is a personal hobby vehicle that we are dealing with, not any customer car and the price of 6 injectors is greater then the value of the car we do not swap out injectors, fuel tank etc since that is simply not worth it.The measuring valve on the old HPFP body was completely covered in shards. Everywhere else in the system there was just some metallic glitter. So we took a chance that the injectors might be a-okay. When we removed the rails, lines and sensors we cound not see any distinct glitter in the parts.

SaVAGeSoot, thats a good point. I will try to block the injectors and see if that results in a pressure build up.

Im fairly sceptical that the injectors are stuck open. There is ZERO smell of diesel while cranking. Today I also removed the glowplugs and let it crank. No diesel and no smell what so ever. Also the HPFP pressure now reads 0 BAR. Even it the injectors would be stuck open, or completely clogged so no fuel could pass through. It seems quite odd that all six would be 100% clogged or leaking all together.

Best of luck.

You should maybe look up how a common rail system works to realize how utterly pointless an endeavor it is to fix a failed HPFP without changing all the parts.

I totally get wanting to fix it etc but your pissing into the wind on that one.