Report on 216 injectors in the AFN

Hello,

Inspired by the posts and the technical article here on the forum, I obtained the 216 injectors from a VW T4 and installed them in my Passat with an AFN engine.
I wanted to check the opening pressure and any potential dripping of the original injectors, especially since they now have 150,000 km on them. The opening pressures of the old injectors were between 170 and 180 bar. No dripping was detected in any of the injectors.
A good tip when changing spark plugs is to briefly start the engine (for about 2 seconds) with the fuel lines not yet connected. After tightening the fuel lines, my engine actually started immediately and ran smoothly after a few seconds. So, no endless cranking, which I had initially feared.
Now, let's move on to the results:
After installing the 216 main jets, I was shocked by the extremely harsh engine knocking compared to the stock jets. I was also very disappointed with the performance increase. During the 2000-4000/min test, I couldn't detect any significant improvement (approximately 6.8 seconds +/- 0.2 seconds).
I couldn't personally confirm the improved exhaust flow that Ulf described, even on the Autobahn. Furthermore, the car produced quite a lot of smoke, especially during rapid acceleration in lower gears (visible in the rearview mirror during the day), which wasn't as pronounced with the standard injectors.
For safety's sake, I rechecked all the relevant values during full-throttle acceleration in 3rd gear using VAG-COM. The boost pressure, fuel injection timing, and air mass are all within the normal range.
The particularly annoying noise from the injectors when driving around town with an open window and partial load is what prompted me to reinstall the original 216 injectors. After putting my old injectors back in, it almost felt like I was driving a gasoline engine; I'm not kidding!
My conclusion is that, for the high price these nozzle holders cost (even if you can find them for €400), the result is absolutely unsatisfactory.
Sorry to Ulf about the technical article, but this is how it turned out for me.

Best regards,
Albrecht.

Hi,

Quote:

Quick acceleration in lower gears results in quite a lot of smoke (visible in the rearview mirror during the day), which wasn't quite as pronounced with the stock nozzles.

A little bit of low boost pressure, huh?
What part numbers are on the nozzles, and what price would you sell them for?
I assume these are new parts and not used or dirty, right?

Best regards, Rainer.

Hello Rainer,

The part numbers are 074 130 201K / 202R, and the engine code is AHY. These were new parts, and I even tested them on a nozzle tester before and after installation to ensure they were working correctly. They all registered at 220 bar, and there were no other abnormalities detected.
I don't have anything for sale; I've arranged things differently, but I won't go into details here.

Quote:

A little bit of low boost pressure, huh?

According to the LDA (likely referring to a specific measurement or standard), there shouldn't be any issues. My VTG (presumably a valve or regulator) seems to be set quite aggressively. I'm already reaching almost full pressure well below 2000/min, and sometimes experiencing overpressure up to 1.45 bar.

Again: from my point of view, I would not recommend changing the injectors. It might be useful for engines with extremely high performance upgrades. However, in everyday use, the disadvantages in terms of cost and noise outweigh the benefits.
Personally, I need more power just for overtaking on country roads.
And that's where the (optional) 10-cent tuning makes a significant difference and costs almost nothing.

Best regards,
Albrecht.

Hello Albrecht,

Did you also check the values of the fuel injection start control while the vehicle was running?

Best regards, Rainer.

Hello Rainer,

Yes, I did: In 3rd gear, at full load, the engine speed was approximately 3000 RPM. The actual and target values were always nearly the same.
My pump's initial setting with the original injectors is slightly advanced but still within the tolerance range, and it might be more accurate when using the 216 injectors. However, I couldn't check the initial setting because I don't have the full software version. I used to do that with a 1551 about 3 months ago.

Best regards,
Albrecht.

Hello everyone,

I've heard from various sources that the injectors alone don't make a significant difference, but only when combined with the 12mm ESP piston. Then, however, it really makes a difference; it's nothing like chip tuning. I find it too expensive, or rather, too much effort.

But: There has been no mention of harder knocking so far, so it would be interesting to know why this occurred. It could be that the pilot injection is missing, but why does it only happen after changing the injector?

Since the nozzles are no longer installed, further measurements cannot be taken. Has anyone else noticed this issue with the nailing process in relation to the 216 components?

Hello Albrecht & Garth,

The diameter of the distributor piston for the ESP can be read from the type number.
This would therefore be interesting.

Example of what such a number looks like: VE4/10E2250R728 (I have no idea what kind of pump this is; I just picked it randomly).

The "4" indicates a four-cylinder engine, and the "10" refers to the diameter of the distributor piston.

Best regards, Rainer.

Hello Garth,

Quote:

The pilot injection might have failed, but why does it only fail when the nozzle is changed?

It can't be due to that, because the pre-injection is purely mechanically realized by the two-spring nozzle holder.
The problem is that there are many other factors besides the hole diameter that influence the air-fuel mixture and combustion process (opening pressure, k-factor of the injectors, etc.).
In theory, everything is good and beautiful, but in reality, it's all just guesswork.
No one knows exactly how, for example, the ignition delay is affected by the altered air-fuel mixture.
Ultimately, the engine would need to be tested on a proper dynamometer with pressure indexing and other relevant measurements.

Best regards,
Albrecht.