Golf IV ALH: 0.205 Injectors from ASV - Compatibility?

Hello.
I installed injectors from a 110 hp ASV engine into my Golf IV with a 90 hp ALH engine.
So far, everything is clear and now it runs smoothly with significantly more power. No problems so far.
However, the engine becomes very, very loud suddenly starting from around 3800 RPM. Otherwise, there are no noticeable issues - the performance is fully there; the ALH accelerates reasonably well up to 190 km/h and then slowly climbs to 200 km/h on the speedometer.

What could be the cause of this sudden loud engine noise? I definitely didn't have this noise before the nozzles.

Best regards,
Bernd

Well, what do you think is the source of the extra power?

Sure, here is the translation of the text from German to English:

'Cu Gremlin'

Thank you for the answer, Gremlin.
"However, the Series 110 doesn't exhibit this phenomenon. I've looked at some charts, and within that RPM range, the ASV actually injects a slightly (though insignificantly) larger amount of diesel. While the boost pressure is somewhat higher, it's almost exactly at 3800 RPM."

Hi,

Okay, something different. How did you even get the nozzles into the ALH?
The ASV has this black connector on the NBF, while the ALH has the brown one.

Greetings.
Thomas.

You can probably find a way to make it work - the cables are the same, right?
I only replaced the injector nozzles.
Best regards,
Bernd.

Hi,

The same old problem. Are you sure your opening pressures are correct?
The connectors are glued or welded together. You would have to cut them apart.

Greetings.
Thomas.

Hello.
We already had that.
The valve clearances have been checked and are within the specified tolerances; they apparently haven't changed due to the modifications.
Best regards,
Bernd

You can actually modify those NBF connectors... disconnect the cables and properly reconnect them to make them waterproof again.

However, as already recognized, the turbocharger boost pressure and injection timing are slightly different on the ASV compared to the ALH, resulting in a different sound.

CU Gremlin.

"So, you consider a sudden doubling of the engine noise at 3800 RPM to be normal and harmless? If the engine speed exceeds 3800 RPM, it suddenly becomes very loud all the way to the rev limiter. If I go below 3800 RPM, it suddenly becomes quiet again."
Best regards,
Bernd

I would need to hear it to evaluate it... all that is certain is that the ALH engine becomes noticeably louder and rougher with larger injectors.

CU Gremlin.

Thank you.
Do you generally consider this to be problematic?

No, generally not.

The ALH becomes louder and more robust with the ASV nozzles. To assess the sound, we would need to hear it...

I'm assuming you've installed the fuel injectors correctly, meaning that the fuel spray angle, etc., is correct.

CU Gremlin.

Hello,

I once considered buying large nozzles at auction, but where does the extra performance come from with large nozzles? Doesn't the amount of fuel sprayed remain exactly the same???

no...

The pump's head remains exactly the same.

However, the larger nozzles present a smaller restriction, resulting in lower injection pressure and, above all, reduced leakage. This leads to an increase in the amount of fuel injected.

The automatic ALH engine is really impressive: it has an 11mm fuel pump (normally 10mm) and 0.158 injectors (normally 0.184). This results in a very high injection pressure (emission class!). However, the fuel quantity remains the same (66 kW).

Always remember, this is high-pressure hydraulics. The VP-37EDC generates up to 950 bar of pump pressure (1250 bar at the nozzle).
A lot passes through gaps that are 2-5µm wide.

CU Gremlin.

AHHH!!

So, the fuel consumption increases, and nothing else happens compared to the '10c/Box' tuning, except that you don't have to inject fuel for as long. This means the combustion should be cleaner than with the '10c/Box' tuning, because you don't have to inject fuel after the piston has already started its downward stroke in the existing combustion process.
I also considered that the existing box/chip tuning might work even better with the use of larger injectors, because this would allow for precise control of the injection time.

My question is actually this:
I observe a significant tendency for soot formation when tuning the engine solely through modifications to the exhaust system.
Does using larger nozzles result in more soot in the exhaust (due to increased fuel consumption or less fine atomization), or does it reduce soot formation (due to an ideal injection timing and duration)?

So, the consumption is increasing.

Under the same driving conditions, no.


and nothing else happens than with the 10c/box tuning.
However, something quite different happens.

10cent EXTENDS the injection duration to achieve the desired amount (resulting in: increased fuel consumption, reduced efficiency, and potential overload).
Nozzles increase the cross-sectional area to achieve the desired amount, while maintaining the same injection time.


My question is actually this:
I observe a significant tendency for soot formation when tuning the engine solely through modifications to the exhaust system.
Ist durch zusätzlichen Einsatz großer Düsen dann mehr Ruß im Abgas(nochmal zusätzlicher Sprit / weniger feine Zerstäubung),oder geht die Rußneigung zurück(Idealer Einspritzzeitpunkt u. Dauer)?

With larger nozzles, the enclosure becomes unnecessary.

CU Gremlin.