Passat TDI: Rough Running When Warm?

Hello.
'For about two weeks, I've been having a problem with my Passat TDI AFN, manufactured in '99. It starts perfectly fine, both when cold and when warm, and runs well when cold. However, as the temperature increases, it starts to misfire. I don't think it's the glow plugs, though. I'm somewhat familiar with this type of issue. It feels like a genuine misfire, not just rough running. The fuel lines are still relatively clean (3-3.5 liters of sediment). It can still reach speeds of around 200 km/h. I don't want to replace all the injectors and then end up having to replace the fuel pump as well.'
If anyone has good advice, I would be very grateful.

Hi Mattes,

Hmm, in your situation, I would rule out the pump in 80% of cases. Since one cylinder supplies pressure to all four injectors, it would be necessary to determine if the misfire always occurs in the same cylinder.

I have 4 fuel injectors here that I could give you for testing. They're a bit dirty because they have 250,000 km on them, but they still work.

What is the engine's mileage?
Is the stuttering also present under full load?
No errors found in MSTG?

There's always something new happening.

Hello Steffarn.
I hope it's not the pump, but I'm also a little worried. This one has 130,000 km on the clock. I've done everything regularly, but it doesn't seem to help. However, I do have the obligatory resistance on the pump. I don't think that's the cause, though. I took four injectors from an AHH engine from work, just for testing. If that doesn't help, or if it runs even worse, I'll get back to you. I'm a bit at a loss myself. But where do you get these injectors so freely available??

AHH is the successor to AHU.

He has smaller holes than the AFN!

Or have I misunderstood something???

m;

Okay, I understand. But I think it should at least run somewhat normally. I just want to see if the jerking/stuttering is gone. I don't really think the injectors would make that much of a difference.

If someone else can help with it, I can lend them the [items] for a few weeks.
They are just lying around here at the moment, and when I have a lot of time and inclination, I will install new nozzle holders. The problem is the nozzle with the NHG, because you can't be sure if it will still work afterwards.

BOSCH is completely refurbishing nozzles for 80 EUR each (regardless of whether they are new, old stock, or standard nozzles).

I've also heard that 220 bar nozzles are supposed to be good for reducing engine misfires (maybe the AHH ones are, since the AHH is supposed to be an EU3 model, or?).

m;

The nozzles are marked with 220/300 bar. Do you think that should work?

dieselmartin wrote:

BOSCH completely reconditions nozzles for 80 EUR each (regardless of whether they are new, old stock or standard nozzles). I've also heard that 220 bar nozzles are supposed to be good for reducing engine misfires (maybe the AHH ones are, since the AHH is supposed to be an EU3 model, or?). m;

@ Diesel Martin

My Bosch technician told me not to disassemble the NHG unit because there's a 50% chance it will be damaged as a result.
no longer working.
I wanted to install the 216 nozzle in my afn injectors and have the opening pressure adjusted to 220 bar.
Do you know if that works? }

They told me on Saturday that it would cost approximately 80 euros per nozzle, and that they could also install NHG nozzles. I specifically asked if those were more expensive or if there was anything different about them.
They denied it.

m;

Hello Steffarn.
What are those 216 nozzle stems supposed to do?

I'm not really an expert on nozzles...
The nozzles from AHH also have a 220 bar opening pressure.
If the nozzle holes are still relatively uniform, then mine should work with them.
I took the reading device home yesterday, but it was empty. (As usual...)
Based on the measurement data blocks, which contain both the target and actual values, it is also possible to...
can't see anything.
'It was running great again... until it reached 90 degrees Celsius after a few minutes, and then it started [having problems].'
turn it on again.

MattesTDI wrote:

Hello Steffarn. What are those 216 nozzle stems supposed to do?

More fuel flows through in a shorter amount of time (tuning).
You should actually know that.
The injectors for the 150hp TDI (5-cylinder) actually have a flow rate of 216 and a pressure of 220 bar.

I haven't looked into the details of the nozzles yet.
Then I'll have to start looking for nozzles like that.

'Something I once experienced, but which hasn't reappeared since.'
It was me, and after a short period of acceleration while it was completely cold, it only reached 2-3 [units - the units are missing from the original text].
'The engine was sputtering and smoking, running terribly, and of course, it had no power left.'
It smelled like soot, so it wasn't burning oil or water.
I also used to put things on social media back in his day (on Rose Monday).