Fuel Injectors AXG: Buy Online Now! | Posts 16+

Hi Ulf,

4 x 074 130 201 T (AXG)
1 x 074 130 204 C (AXG)

This is the 110kW 5-cylinder TDI engine from the T4 Caravelle.
Theoretisch funktioniert das auch mit den Einspritzdüsen aus dem AHY-Motor. Das ist ebenfalls ein 110KW 5Zyl. TDI engine.

These injectors would then have the part number...

4 x 074 130 201 K (AHY)
1 x 074 130 202 R (AHY)

Unfortunately, I don't have a Bosch part.
The new price at VW is 1002 euros, including VAT.


So...

The Bosch part number 074 130 201 K (AHY) corresponds to part number 0 986 430 408, which costs €87.30.
and for 074 130 202 R (AHY), the number is 0 986 430 556 (125€).

costs together for a 4-cylinder engine, €386 .

Is that possible, or not?

@Maciek: YOUR LINK IS SUUUUPER!

@Thomas: Are the nozzles from the AHY engine really equivalent to those from the AXG (T4 engine)?

Regards,
Michl.

MichlM wrote:

The Bosch part number for 074 130 201 K (AHY) is 0 986 430 408 (priced at €87.30). and to 074 130 202 R (AHY), it is 0 986 430 556 (€125). costs together for a 4-cylinder engine €386.

Hi.

As far as I can tell, you've already figured out the exchange rates.

Without a "deposit return" option, a set of injectors for a 4-cylinder engine really costs around 1000 euros - whether it's from Bosch or VW .

...as far as I can tell, you have determined the exchange rates.

Without a 'deposit return' option, a set of injectors for a 4-cylinder engine really costs around 1000 Euros - whether it's from Bosch or VW .

Oops, that might be the case. .
.... 1000 Euros ???? That's outrageous!

Regards,
Michl.

Hi.

Are you sure the AFN piston looks the same as the one for the 75 kW engine? Where did you get that information?


'Genauso' refers to the appearance of the depression (i.e., 'round and smooth').
It's clear that the pistons are not identical due to the bore.
I can take a picture of the AFN piston when I get a digital camera.
Appearance isn't everything either, because apparently VW treats the materials differently, resulting in varying strengths and other properties.



At least, the lower, flared portion of both pistons seems to have the same diameter.
From this, one can infer that the burning fuel injected by the large nozzles certainly does not impact the piston material with excessive force...

If the larger nozzles deliver the (increased) full load amount more quickly into the combustion chamber, the piston is closer to TDC (Top Dead Center) at the end of injection, and the heat load on the upper edge of the combustion chamber will be lower (where piston melting typically starts first).

How will the 220 bar pressure likely affect the start of the spraying process?
The pressure inside the cylinder is probably also higher.
If such an engine could last 60,000 to 100,000 kilometers, that would be fine with me .
The Bosch service should also accept used AFN injectors as deposits.
And if you can get a discount, the cost for new T4 injectors would be around €400.

Regards,

Maciek.

Maciek wrote:

How will the 220 bar pressure likely affect the start of the spraying process? The pressure in the cylinder is probably also higher.

Hi.

190 or 220 bar is "just" the opening pressure.

220 bar will naturally be reached a bit later than 190, meaning the injection start will be later (how much = should not really be a problem -> just adjust the pump earlier and it's done).

As far as I know, much higher pressures are reached during the actual injection process, depending on the engine speed.

However, with a larger injector diameter, the injection pressure is generally lower (at the same flow rate or speed) than with the original injectors.

Quote:

If such an engine were to last 60,000 to 100,000 kilometers, that would be acceptable to me.

Only with the larger nozzles are we likely (based on my current estimate) to see an increase of around 11% in performance.
As long as you're not using a full-surface bottom plate and an (in my opinion, not yet definitively ruled out) unsuitable spray pattern from the larger nozzles doesn't melt the original pistons, a modified engine should practically achieve its normal lifespan.

However, due to the lower injection pressure, the average soot formation could be higher, which could lead to faster clogging of the intake manifold with oil-soot deposits (as long as the EGR system is functioning).

@ulf

Do you want to get some performance tuning done now?

Regarding the nozzle prices: they are about the same as those for the 1Z. In my opinion, the prices listed above do not include any additional taxes or fees.

I paid approximately €370 before Christmas 2002, but I received about a 20% discount!

joergs wrote:

@ulf Do you want to get some performance tuning done now?

Hi Jörg,

No, not yet - there are still too many unanswered questions for me.

But I find it interesting to specifically examine this topic, which has been circulating in the forum for some time, in order to gain some clarity about the facts and the myths surrounding it.

I'm still missing posts from the real pump and injector specialists.
Bertil, Gustav... where are you?

Hello Ulf,

Regarding my performance evaluation, I can unfortunately only say that I am very, very skeptical about the whole thing.
If you like, I can scan the text and send it to you.

Quote:

220 bar will naturally be reached a bit later than 190, meaning the injection start will be later (how much = should not be a real problem -> adjust the pump early and it will be fine)

Could it be that if you delay the start of fuel injection to a point that's roughly equivalent to that of the stock injectors, and then reinstall those stock injectors, the engine will stall immediately after starting?

Greetings.
Thomas.

Thomas wrote:

Could it be that if you delay the start of fuel injection so much that it roughly corresponds to the timing of the original injectors, and then you reinstall those original injectors, the engine dies immediately after starting?

Hi Thomas,

Off the top of my head , I would say that the increase from 190 to 220 bar should be so rapid that any necessary pump correction (if needed at all) would likely be minimal - and that this small amount shouldn't ruin the starting behavior with the standard injectors.
The main problem is usually the initial start-up. If the engine stalls from the idle speed, it's likely due to different causes than WFS (presumably referring to a specific issue), or possibly air bubbles in the injector lines.

Have you ever compared the start of spraying (or the spray regulator setting ratio) using normal and large nozzles ?

...and an (in my opinion, not yet definitively ruled out) unsuitable spray pattern from the larger nozzles doesn't cause the original pistons to melt...



Hello everyone!

Okay, I'm going to ask a question, as a complete newbie to this forum, that hopefully isn't too dumb:

Perhaps someone can compare the location of the injector nozzle holes? (e.g., comparing the holes in a 150hp T4 engine with those in an AFN engine).

I think that if the position of the holes (and therefore the direction of the spray) is the same, and the number is the same anyway, and only the bore diameter is larger (so instead of 0.205mm, it's 0.216mm), then the spray pattern probably can't be that different... it's just that more material is injected in roughly the same direction and burned... or am I completely wrong about that???

Hi Michl!

MichlM wrote:

I think that if the position of the holes (and therefore the direction of the spray) is the same, and the number is the same anyway, and only the bore diameter is larger (so instead of 0.205mm, it's 0.216mm), then the spray pattern probably can't be that different... it's just that more material is being injected in roughly the same direction and burned... or am I completely wrong ???

Hi Michl,

The matter is probably not quite so simple.

For example, it is said (i.e., I haven't seen it in person yet) that injectors with high mileage may atomize the diesel fuel much less effectively, possibly due to deposits and/or "worn" boreholes.

And I still believe the differences between a new and a worn nozzle of the same type are smaller than the differences between two nozzles of different types.

For example, it is said (although I haven't seen it firsthand) that nozzles with high mileage significantly reduce the quality of diesel atomization, possibly due to deposits and/or 'worn' boreholes.


mostly the latter. The geometry of the holes is a science in itself. The inlet and outlet edges are specially shaped, etc. However, at high pressures, wear and tear occurs over time, even with materials that are extremely hard, like those used at 2000 bar. And even the smallest bit of dirt contributes to the problem. As the saying goes, 'constant dripping wears away the stone.'

I still haven't found a list that describes the various nozzles.

CU Gremlin.

Are you sure the AFN piston looks the same as the one for the 75 kW engine? Where did you get that information?



Yes, yes It's embarrassing when you tell nonsense .
While taking pictures, I realized that at first glance, I...
I was smitten.
The piston also has this 'pointed' indentation. Hopefully, it's visible in the picture.
See the picture.


Sorry.

Maciek.

Maciek wrote:

The piston also has this "pointed" indentation.

I hope you can see it in the picture.

Hi Maciek.

Thank you for the picture; the tip is clearly visible.

Is that an AFN piston?
If so, the only thing that needs to be clarified is whether the combustion chamber of the AFN engine is smaller than that of the 2.5-liter engine (hopefully not).
Because with significant differences, it is my opinion (IMO) that the burning spray from the large nozzles could "impact" the wall of the AFN combustion chamber and cause overheating/melting damage, etc.