Idle Speed Control: Values Significantly Worsened

Golf 4, ALH engine, 211,000 km, all original.

Hello, the third cylinder is misfiring... it looks like this...

Cylinder 1: -0.45
Cylinder 2: -0.35
Cylinder 3: 1.0
Cylinder 4: -0.2

Three months ago, they were all in the range of 0.2 to -0.2.
When the engine is cold, it shakes noticeably, and this has become much more pronounced in recent weeks. Cold starting is also not very good. The glow plug system is in perfect order. A longer pre-glow time, or pre-glowing twice, helps the engine start better.

Are the nozzles or the pump the problem?
I suspect, based on everything one reads about the injectors, that the sound of the combustion is quite dull, and not very much like a TDI engine.

'I would replace the nozzles too, if I didn't have to drive the car every day...'

What's the quickest and cheapest way to do it? Has anyone ever replaced the injectors themselves, including the needles? Is the NBF (Neutral Balance Fuel) a problem?

Mario oh oh oh.

Hello flightmaster,

With 211,000 kilometers on the clock, the injectors are likely nearing the end of their lifespan.

How did you actually measure the 3rd cylinder ? It serves as a reference for the other cylinders. At least, that's how it is with mine, the AFN .

In Bosch's service department, only the 'standard' injectors (not the ones with NBF) are repaired, and even then, they are not particularly enthusiastic about doing so!
The NBF nozzle is only sold as a complete unit (this is my own experience from our BOSCH service department).

In our case, it looks completely different . Our administrator also repairs the nozzle using NBF. And that's at a fair price .

The injector assembly (complete injector unit) is also described on its injector/tuning section, and with a little technical knowledge, it's not rocket science.

Just ask (it doesn't cost anything, after all). Or simply take a look in the shop!

However, replacing the injector nozzles themselves (the nozzle with the needle) is not easy, because afterwards, the nozzles need to be checked and adjusted to the correct opening pressure. I would advise against doing that.

Sincerely,
K. Oldewurtel

So, that's how the values are displayed in VAG-COM.

I've already considered swapping the injectors at Rainer's, but I really want to keep the engine in its original stock configuration.
Rainer only offers tuning nozzles, not nozzles for ALH engines. (I think they are 0.187 in size).
Besides, I need the car almost every day.
I live in northern Germany, so only postal shipping is an option. That will likely take a week or longer.
That would then require planning at the general staff level.
I'm open to all options (e.g., express shipping).

Mario.

oldewurtel wrote:

How did you actually measure the 3rd cylinder ? It serves as a reference for the other cylinders. At least, that's how it is with my AFN

. . . but not with every MSG data set. Newer ones indicate the deviation of all cylinders from the average.

Hi Mario,

Don't worry, I will also replace all the nozzles with original-size replacements.
http://shop.dieselschrauber.de/product_info.php/cPath/36/products_id/281

I wouldn't worry too much about the LLR (likely lifetime remaining) values, as there are cars with significantly fewer kilometers that have worse values.
As long as no single value starts to deviate significantly, I think you can sleep soundly at night. Of course, old, but evenly worn nozzles can significantly increase fuel consumption, but there's no need to panic and take drastic measures.

Best regards, Rainer.

Hello Rainer,

Thank you for the reassuring words.

What timeframe would be possible for a colonic irrigation treatment at your clinic? This would help me with my planning.

Mario.