sporadisch starkes Nageln, dann wieder weg | Posts 32+

Hi!

There is news, and it's not good. The injection start controller (SBV) is electrically fine.

Here are the values I measured:

- Resistance: 15 Ohms
- Power at 12V, 0.8A.
- Battery voltage with the engine running and the battery management system connected: 13V (measured using an analog meter).

Here are the things I noticed:

- A distinct clicking sound is audible when voltage is applied (motor is not running).
-When the automatic belt tensioner (SBV) is engaged or disengaged while the engine is idling, the engine noise changes, and there is a knocking sound in both cases.
- While driving with a damaged or disconnected short block vibration (SBV) cable, experiencing significant knocking sounds.
-While driving with the trailer attached, there is a moderate knocking sound. Sometimes, the knocking disappears, and the engine has incredible acceleration! (But this only happens rarely; as soon as you start putting some load on the engine, the knocking returns and it doesn't 'recover').

Does that mean the piston in the SBV hydraulic system is sticking? How can I salvage the SBV?

Help!

SeatArosa1.7SDI wrote:

Does that mean the piston of the SBV hydraulic system is difficult to move?

Either the connection between the engine computer and the SV valve is faulty, or there's something wrong with the hydraulics... but unfortunately, it looks more like a hydraulic issue to me.

Okay, here's a really dumb question:

Can the ESP not be disassembled and cleaned? I know that's a delicate matter, and it's difficult to put everything back together with µm precision. But is there a way to expose the SBV piston somehow without completely disassembling everything total? If I have to get a new ESP, I will definitely keep the old one and try to repair it.

Since the error disappears intermittently, it's likely not a broken component, but rather something that's just getting dirty, right?

First, I'm going to use a can of Liqui Moly. http://www.liqui-moly.de/web/lmhomede.nsf/pages/index_produkte There are two options: Should I use the diesel flush or the diesel system cleaner? (If searching, type 'Diesel'). On the Liqui Moly website, it said something about the system cleaner being 'For the JetClean device,' and that device is sold separately. What is that? Can you not use the can without that device?

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

'Hello.'

Hi Ulf.

or there's a problem with the connection between the engine computer and the SV.

To completely rule this out, I'm going to apply an external constant voltage to the SBV. If the SBV piston ever switches, the knocking should disappear and the SB should go to 'late.'
The chances of an electrical cause are slim. The 13V SBV voltage plus the 'nailing' indicates that the EDC is unsuccessfully trying to shift the actual SB value towards a later time, am I understanding this correctly?

Best regards,

There is news.

I took a test drive with a variable speed pump system powered by a cigarette lighter adapter.

Idle:
- SBV without 14V: easy nailing.
- SBV with 14V: More powerful and 'robust' riveting.

From partial load to full load:

- SBV without 14V: powerful hammering.
-SBV with 14V: no hammering

In both cases, however, there was hardly any progress.

A particular observation: The background noise changes when the 14V is turned on or off, but sometimes very slowly.

Does this confirm the theory that the SBV valve is difficult to operate and no longer allows for fine adjustments? In other words, it only moves abruptly when switching on or off the full 14V?

Regards,

and thank you in advance for as many comments, suggestions, and opinions as possible .

SeatArosa1.7SDI wrote:

The chances of an electrical cause are slim. A 13V SBV voltage + a "nailing" event indicates that the EDC is unsuccessfully trying to shift the actual SB towards a "late" position; am I understanding this correctly?

Yes, at least that would be the case with the TDI.

Quote:

The background noise changes very slowly when the 14V is turned on or off sometimes. Does this confirm the theory that the SBV piston is difficult to move and no longer allows for fine adjustments? In other words, it only moves jerkily when switching on or off the full 14V?

It could very well be that way.
I don't have any personal experience with such cases or symptoms, so everything below is just "theory" .

I don't have any personal experience with such cases or symptoms.

Und was sagen die anderen Cracks zu den Symptomen? gremlin? dieselmartin? Bertil? Donalexo?

Best regards,

"Well, to me, that also sounds like a stuck fuel injector."
The solenoid valve only controls the throttling mechanism in the fuel injection pump.

Deshalb kann das Magnetventil völlig in Ordnung sein und den Innendruck der Pumpe vorbildlich modulieren, das ändert jedoch leider nichts an der Position des Spritzverstellerkolbens, wenn dieser mechanisch feststeckt. Die Rückholfederkraft kann nicht künstlich erhöht werden. So kann ich mir nur vorstellen, dass eine Betriebspunkt jenseits der "Steckposition" hilfreich ist, um den Kolben evtl. zu lösen. D.h. wenn man Drehzahl und Last stark erhöht, damit der Spritzbeginn nach sehr früh verstellt werden muss, dann wird der Kolben vom Pumpeninnendruck über die "Steckposition" gedrückt. In diese Bewegungsrichtung hat man wesentlich mehr Kraftpotenzial, da der Innedruck auf den Stellkolben wirkt. Für den Rückhub gibt es nur die Federkraft. Danach könnte man z.B. Auskuppeln, um den Sollwert nach maximal spät zu kriegen. Dieses Spielchen, also mit Vollgas bis 4000 1/min beschleunigen und anschließend auskuppeln in häufiger Folge wiederholen, am besten noch in Zusammenhang mit Dieselspülung. Vielleicht kriegt man so den Kolben wieder frei. WeIf not, then a mechanical procedure is probably the only solution, which involves disassembling the pump.

Good luck.

Regards,
Alex.

Hey everyone, hey donalexo.
Right now, I'm still gathering information about the VP37. If anyone has any drawings, exploded diagrams (with explanations), or photos, please send them to me at [email protected].

Since I have a relatively exotic engine , I'm wondering if I could use a common VP37, for example from an AFN, as a replacement. That would increase the chances of finding something like that at a reasonable price (in case I need to replace the ESP).
In what specific details do they differ? It's already clear that the maximum flow rate must be higher. Does the pump piston have a larger diameter or a longer stroke?

Best regards,

SeatArosa1.7SDI wrote:

Und was sagen die anderen Cracks zu den Symptomen? gremlin? dieselmartin? Bertil? Donalexo?

.... Du willst im Ernst eine Aussage dazu? ... Okay...

I've been following the entire thread with a shaking head, because once again someone doesn't want to accept that the VP37 was designed as a "wear part" (in my opinion, a pump piston running in an aluminum housing cannot last forever).
Unfortunately, issues with the hanging injector nozzle or fuel metering system are not uncommon in the VP37 injection pump. I suspect you're now experiencing one of these problems.

donalexo wrote:

This little game, which involves accelerating to 4000 RPM and then disengaging the clutch repeatedly,

Hi Alex,

IMO, you don't necessarily need to drive for that.
Disconnect the injector control module (ICM) and apply battery voltage to it using a manual switch.

Then, while standing still, alternate between...

-> ohne Spannung am SV weit hochdrehen (bis einem der Motor leid tut) -> maximaler Innendruck und max. Early promotion.

-> mit Spannung am SV auf Leerlauf zurückfallen lassen -> max. Late adjustment.

The chances of success are, in my opinion, low (see also Bertil's answer), but at least you can save a few drops of diesel by trying .

Bertil wrote:

Quote:

I have only watched the entire thread with a shaking head, because here again someone doesn't want to acknowledge that the VP37 was designed as a "wear part" (a pump piston running in an aluminum housing cannot possibly last forever, in my opinion).

Essentially, your statement is probably correct, as nothing is built to last forever. However, the sliding surface of the aluminum bushing is coated with a very hard C-layer to reduce friction (for smooth operation) and minimize wear. I'm not exactly sure which coating process was used there at the moment; I suspect it might be a Diamor coating.
I myself have already driven with such coatings and was very surprised by their effect.
One should not jump to conclusions about material pairings too quickly, as surface coatings also play a significant role.

Regards,
Alex.

Hi,

Even though the SDI-VP37 likely uses different pistons than those found in a TDI engine, I assume that the stress on the pump and its components in a 1.7L naturally aspirated diesel is significantly lower than in a 1.9L turbocharged diesel – or am I mistaken?

"The VP37 is undoubtedly a wear part, but to fail after only 93,000 km in an SDI engine?"

Best regards,

January.

It seems someone here doesn't want to acknowledge that the VP37 was designed as a wear part}.

'Although 93,000 km isn't exactly a lot for a VP37, is it, Bertil?'

To go back to my question about a major accident: Let's say I somehow get a good deal on a VP37 from AFN or somewhere else.
Is it possible to somehow transplant a more powerful VP37 injection pump into my AKU engine? For example, by electronically reducing the maximum injection quantity using the signal from the quantity control potentiometer, essentially doing the opposite of what's achieved with Powerbox or '10ct' tuning?
The entire setup would be less about avoiding smoke and more about preventing excessive strain on the pump and timing belt (since, in this case, a pump that is too large would be working with injectors that are too small).

Thank you in advance for your comments.
Regards,

'@ulf: You're right, I've been manually activating the starter battery voltage (SBV) via the cigarette lighter socket since yesterday. This helps reduce the peak voltage and allows me to drive without problems, even in city traffic.'

that the stress on the pump and its components is significantly lower in a 1.7-liter naturally aspirated diesel engine than in a 1.9-liter turbocharged diesel engine - or am I mistaken about that?

Hi Jan6k! If the AKU had the same pump, but in a throttled form (reducing the maximum injection amount), like for example the AFN, then your theory might be correct. However, the maximum pressure should probably be approximately the same (the AKU has smaller injectors, so pressure builds up faster), only the flow rate would be different.
The stress on the injection start adjuster piston is likely the same in any case, as it operates independently of the injection volume and injection pressure. Am I understanding this correctly?
Best regards,

By the way, I've noticed that others don't just identify themselves by their car or sign with a name, and since 'Regards, Seat' is silly, I'm now also signing with my actual name .
Best regards, Holger.