Audi A6, 1995, AEL, 150,000 km, starting to spray (550)

Hello.

Hmpf, not a very descriptive title, but hopefully a few people will still read it .
Please don't immediately start suggesting solutions involving the 550 error or the search function; I have a slightly different problem.
'Yesterday, I was driving on the highway and decided to try out the top speed. Suddenly, the engine cut out at 4000 RPM, which startled me because it had run faster before. I thought it might be the same issue I had experienced previously (although it cut out earlier then), so I immediately took it to the workshop and had the error codes read. It was clear: a '550 regulation difference' error. So, I checked the fuel injection start timing, and it's actually on the ideal line.' Therefore, the start date of the funding aligns well with my plans, and I'm almost at the end of my brainstorming phase.
Resistance from N108 measured = 15.9 Ohms (should be 14-1, so it's also within the acceptable range.
While the engine is in its basic setting, the N108 sensor is disconnected, and then the pump should start at its maximum advance setting, displaying '225' in field 2 (indicating the start of fuel delivery). However, mine isn't doing that; it only reaches a maximum of 215. According to Audi, ... Is it really necessary to create a checklist before replacing the pump? Surely not?
I have to say that this is the first time it has happened, and I also have an implant. It's actually a 'good' chip, so I'm basically ruling it out.
Pollution in the EP?

I hope you can help me now...

Thanks & Regards,
Mario.

Nobody
Did I write that in a way that's too offensive, or is there no one who can/wants to help me ?

Mario.

Diesel filter replacement?

Gottlike wrote:

While the engine is in its basic setting, the N108 is disconnected, and then the pump should start at the maximum advance setting, displaying "225" in field 2 (indicating the start of fuel delivery). However, mine doesn't do that; it only reaches a maximum of 215. According to Audi, Checklist before replacing the pump, but that can't be right, can it?

Why not?

If the electronic actuator is disabled, the sensor range (NBF -> checked?) along with its evaluation, as well as the fuel lines, must also be included. If the filters are intact, and the "mechanics" aren't doing what they're supposed to, where else could the problem be?

Whether the pump needs to be replaced or can potentially be repaired is a matter for another discussion.
-> Worn-out diaphragm pump?
-> Is the fuel injector stuck "just before closing"?
-> Return throttle too large (or has a type of bypass formed in parallel)?

It could be related to the fuel system. As Rainer already wrote: A diesel filter could be a potential suspect.

However, other possibilities include air in the fuel line and a blocked fuel tank vent.

So, the fuel filter is new.
Air is also not visible.
I should probably check the fuel vent.
I'll also try out NBF sometime (it only worked with the ping test - correct?).

'Under normal driving conditions, I also don't experience any problems; the engine even revs above 4000 RPM without triggering the error.'

Thank you in advance...

Mario.

Gottlike wrote:

During normal driving, I also don't experience any problems; it even revs above 4000 RPM without triggering the error.

Okay, let's log the start of the injection, hopefully we'll see more data from that.

Then, please log the start of the injection, from which we should (hopefully) see more.

I would like to, but I can't right now because I don't have access to a diagnostic tool or VAG-Com.
I will definitely keep that in mind.

Best regards, Mario.

on to the second round

Today I drove the car again, and lo and behold, it now regulates a few km/h later .

NBF tested with a knock test; the engine continues to run smoothly without any misfires or similar issues.
As I mentioned, the fuel filter is new, and the fuel vent is also working correctly.
I had slightly adjusted the start of the injection timing away from the ideal setting, and I bought one bottle of 'diesel cleaner.' Well, both probably worked with varying degrees of success.

My suspicion is now really leaning towards the pump.
What do you think, should I maybe just replace the NBF (needle bearing flange) as a precaution?

Best regards, Mario.