G2 TD (JR): Ladedruck > 0,5 nur bei starkem rußen möglich | Posts 16+

Is your exhaust clear? Is there a catalytic converter in there that might be clogged?
Turn the fuel screw outwards until it starts to sputter slightly, as you won't be able to proceed otherwise. If you've found the problem and the fuel screw is turned too far inwards, it still won't produce more power.
Is the boost pressure enrichment okay?
Have you already measured the LD (load) in your Jetta using your LDA (laser Doppler anemometer)? I'm not sure if a 75 hp engine can reach 160 km/h with only 0.25 bar of boost.
Are the intake pipes clear (from the air filter to the turbo)?
Someone wrote to you suggesting that you should check for broken studs on the intake manifold. Have you done that? You mentioned it yourself:
"At very high RPMs - and, to my knowledge, only at these RPMs is any noticeable LD (lean detonation) produced - a small puff of exhaust suddenly emerges from the area below the turbo, roughly on the intake side."
Have you checked that?
Everything must be perfectly sealed between the engine block and the turbocharger, otherwise there will be no boost pressure.

Does your engine have an exhaust gas recirculation (EGR) system? Is it possible that the boost pressure could be escaping through a different hose or valve?

"Can't you swap the charger with one from a Jetta? Then you'll know if the problem might be with the charger itself."

Is your exhaust clear? Is there a catalytic converter in there that might be clogged?
Adjust the fuel screw until you hear a slight sputtering, as you won't be able to proceed otherwise. If you've identified the problem and the fuel screw is turned too far, it still won't produce more power.
Is the boost pressure enrichment okay?
Have you already measured the LD (load) in your Jetta using your LDA (laser Doppler anemometer)? I'm not sure if a 75 hp engine can reach 160 km/h with only 0.25 bar of boost.
Are the intake pipes clear (from the air filter to the turbo)?
Someone wrote to you suggesting that you should check for broken studs on the intake manifold. Have you done that? You mention it yourself:
'At very high engine speeds - and, to my knowledge, only at these speeds is any noticeable LD

So, the exhaust system only consists of the muffler, and I replaced that last month, but there's been no improvement.
'When I adjust the set screw, I can achieve LD values up to a maximum of 0.4 bar, but there is significant noise at the lower end of the range.'
I checked the LDA, the membrane is fine, and the pin extends when I manually move the throttle lever.
The Jetta is currently deregistered (it's my wife's winter car), so I can't measure the LD (light distribution) on it.
However, I directly connected the LD display once, and the displayed value was very close to the value shown by the air pump (1 bar).
I've already replaced all the intake manifolds, including the air filter box and air filter, but there's been no improvement.
Regarding the studs:
I recently heard loud noises coming from the area, and upon inspection, I discovered that I had lost three of the eight studs. I thought that was it! But when I bought replacements from VW and reinstalled them, the rattling and noise disappeared, but the LD (likely referring to a measurement or value) remained very low.
Exhaust gas recirculation: NO.
The pressure relief valve on the intake manifold has already been replaced with the one from a Jetta, but there's been no improvement.

Regards,
euro

Hmmm, if the exhaust valve and exhaust system are clear, and the fuel mixture screw is adjusted to increase the fuel mixture, but there's still black smoke, then either the wastegate valve might not be closing properly. Unfortunately, you can't see it directly on a KKK turbocharger. To see the wastegate valve, you'd have to remove the exhaust pipe directly connected to the turbocharger. Alternatively, the turbocharger itself might be failing. You could try turning the boost pressure limiting screw on the wastegate housing further in; this might increase the boost pressure. That's how I increased the boost pressure to 1 bar on my old Golf.

Hi, I think the T3 server is the closest match.

"I also had this problem with a Golf 1, 1.6 TD. In this case, the pressure sensor that opens the wastegate was directly mounted to the exhaust manifold (which is probably the case for all older models, unlike the externally mounted diaphragm sensors that use a linkage to actuate the wastegate)."

Typically, the spring tension of the spring, which works against the boost pressure (via the diaphragm of the canister), is adjusted by screwing in the #6 adjustment screw (with a locking nut). This determines the opening pressure of the wastegate. Screwing it in increases the opening pressure, which in turn increases the boost pressure.

The disadvantage of this can design is that the spring, over time, becomes fatigued due to the fluctuating temperature changes, which gradually reduces the opening pressure.

To a certain extent, it is possible to adjust the valve, but if the spring is too weak, further tightening of the adjustment screw until it reaches its limit will only cause the wastegate to close directly, which will then no longer function (consequence: excessively high boost pressures, damage).

I haven't been able to swap the housing yet. The three M6 Allen screws are no longer removable without causing damage (even with heat).

I've now turned the adjustment screw another half turn. The result: the LD (likely referring to a measurement) has increased from 0.25 to just over 0.5.
'However, it already produces quite a bit of black smoke when driven at low speeds.'
Even when driving at full throttle, I couldn't detect any soot. (The speedometer now indicates a maximum speed of 170 km/h).

I then tightened the adjustment screw another 1/3 of a turn. The highway test is still pending.
But: The idle speed is now 1800 RPM!!

Is that adjusted at the back of the long rod on the ESP?
'On my ESP guitar, the upper part of the tremolo arm was once damaged, and since then, a small (possibly a 5mm?) nut has been placed on it to provide tension for the spring.'
Question: Does the idle speed decrease when the spring is tensioned or released? I don't have any room to release the spring any further.

Is it even normal for the idle speed to be that high? I mean, I've read that the idle speed may need to be adjusted after adjusting the fuel mixture screw, but has anyone else experienced such a large difference?

Regards,
euro

The normal path of a metering screw also has a beginning and an end.
This is likely something you've experienced. It manifests as an uncontrolled increase in the idle speed.
You can't compensate for this anymore, even with the "long rod" that I described. The long rod acts on a lever (at the top) via the choke cable mechanism (located at the bottom of the pump, which adjusts the injection timing to be earlier). The travel of this lever is then adjusted using two 6mm screws. This is where the idle speed adjustment is set within the normal operating range of the pump.

If your engine makes a lot of noise at low RPM but not at full load, it's likely that your boost pressure enrichment is incorrectly adjusted (it's cutting off too early).

While there is a relationship between the energy output of the engine, which depends on the fuel injection amount, and the boost pressure, it no longer makes sense to try to increase the boost pressure with even more fuel injection once the Russian border (presumably a limit) is reached. First, the boost pressure needs to be brought up to at least the minimum target value.

What I don't understand is that you're not trying to find the cause of the insufficient boost pressure.

It's also possible that the fuel injection pump is likely a model from the 1.6-liter engine without a lambda sensor, and it may not be sufficient for the larger fuel injection volume required with a lambda sensor (its regulation limit has been reached, as mentioned above).

cetano wrote:

What I don't understand is that you're not looking for the cause of the insufficient boost pressure.

Hi,

I have to agree with Cetano. You're "tinkering with the wrong things"!
By systematically analyzing your problem, you can often eliminate many possibilities beforehand.
It's quite unlikely that the low boost pressure is due to insufficient fuel injection. If the fuel injection volume were so low that it only produced 0.5 bar of boost (with a KKK K14 turbocharger) even at high RPM, your engine would only be injecting fuel equivalent to about 30 horsepower (or something similar). And it would also hardly produce any soot.

"The standard fuel injection pumps for the 1.6 TD engine all provide enough fuel for the small turbocharger. Even the ESP (Electronic Stability Program) fuel pump from the naturally aspirated diesel engine would generate enough fuel pressure in the higher RPM range to achieve 0.8 bar of boost pressure."

If the intercooler piping is 100% airtight, the problem must be located within the turbocharger itself. This could be due to the wastegate opening too early (or not closing completely), or the compressor being damaged, with the shaft running with excessive friction, etc.

Remove the turbocharger and have an expert inspect it (e.g., www.turbolader.com).
And please disconnect the water supply to the turbo, otherwise even a rebuilt one won't last long.

Edith says:
My Golf II with the original 1.6TD engine (MKB SB, 59 kW) had a top speed of 185 km/h according to the speedometer, which was probably closer to 175 km/h in reality. However, the engine was already running close to the redline at that speed.

Regards,
Jens.

Thanks for all your suggestions so far.
By the way, I have a Garrett turbocharger in the Golf (the part number is 466534-0005, which, according to Google, is a TBO218). The KKK turbocharger is the original one in the Jetta.
The Garett turbocharger does not have an adjustment screw on the wastegate pressure sensor.

I can move the rod connected to the wastegate valve with a noticeable amount of resistance, and it also makes an audible 'pop' sound when released.

I've now adjusted the mixture screw so that the LD (lambda value) is still around 0.5 and the idle speed is approximately 100 RPM. I haven't adjusted anything on the long screw for the idle speed yet. VMax (maximum speed), measured today: approximately 175.
Yesterday, it was still making a significant rattling noise with that setting, but today it's almost completely silent, even when driving at low RPMs.
Originally, the pump also had a performance nozzle, which I replaced with the original one from a Jetta; just mentioning that as a side note.

I manually moved the turbo again, and it only has extremely minimal shaft play, and it spins just as smoothly by hand as the one from the Jetta.

Therefore, I still believe that it might be related to the pump.
(INFO: I'm not ignorant, and I appreciate your suggestions regarding troubleshooting the turbocharger. However, I'm hesitant to remove the part because I need the car every day.)
'Or can someone here briefly explain the best way to remove and install the turbocharger? Do I need a pit? What tools are needed to spread the clamps on the downpipe? Or can it be left in place? What new gaskets are required?'

'I mean, with the current performance, I'm already quite satisfied. If I didn't have this LD indicator, I wouldn't even think that something might be wrong.'

Could there be a reasonable explanation for why the Russian team (with the same level of preparation) sometimes performs well and sometimes barely shows up at all?

According to the previous owner, the ESP was optimized by Oettinger, but he couldn't provide more specific details. Does anyone know what modifications Oettinger typically makes to the ESP?

Regards,
euro

euro wrote:

By the way, I have a Garrett turbocharger in the Golf (the part number is 466534-0005, which, according to Google, should be a TBO218). The KKK turbocharger is the original one in the Jetta.

The Garrett TB 0218 and the KKK K14-6087 were used interchangeably by VW, and they are aerodynamically equivalent.

Quote:

The Garett turbocharger does not have an adjustment screw on the wastegate pressure sensor. I can move the rod connected to the wastegate valve with a noticeable amount of resistance, and it also makes an audible "pop" sound when released.

Okay, and at what boost pressure does the wastegate open?
You won't be able to answer this question, but it's important for the functionality. That's why my suggestion to consult a turbocharger expert.
The target boost pressure in the RA/SB system is 0.8 bar.

Quote:

According to the previous owner, the ESP was optimized by Oettinger, but he couldn't provide any more specific details. Does anyone know what modifications Oettinger typically makes to the ESP?

Common practices of tuners:
Exchange the tax bracket for a slimmer one.
Adjust the quantity control screw until soot appears.

It's ready, costs 800 euros, and takes 1 hour.

Other modifications, such as a larger piston in the ESP (Electronic Stability Program) or a larger LLK (likely referring to a component), or something similar, are typically not done, as they would also cost around 3000 euros.

Regards,
Jens.

Hello Jens,
(and to everyone else who has responded), thank you for your help in finding the cause! I'm really happy because now, after 2.5 years, I finally feel like I'm very close to a solution.
Maybe it will work out! It would be a shame to get rid of the car, as there probably aren't many others on the road with this (full) equipment. Otherwise, everything about the car is perfect and everything functions flawlessly, except that I haven't been able to get the performance I need.


Okay, and at what boost pressure does the wastegate open?
You won't be able to answer this question, but it's important for the functionality. That's why my suggestion to consult a turbocharger expert.
The target boost pressure in the RA/SB system is 0.8 bar.
Jens

To determine this, wouldn't it be sufficient to disconnect the pressure hose from the can and observe during the test run whether the LD (likely referring to a pressure or level reading) continues to increase?
I had already done that, but it didn't change the LD in any way.
There's still the possibility that the wastegate valve isn't sealing properly, which could lead to constant pressure leaks. (Or that the turbocharger/exhaust manifold has a crack somewhere.)
Would removing the four screws from the trouser leg be enough? Would I then be able to bend it to the side so that I can see the wastegate valve? Or do I need to remove the brackets? (-> To do that, I would first need to acquire the appropriate tool.)


Regards,
euro

euro wrote:

Wouldn't it be sufficient to disconnect the pressure hose from the can and, during the test run, observe whether the LD continues to increase? I had already done that, but it didn't change the LD in any way.

Hello Euro,

Which hose did you disconnect exactly?
The one that runs from the turbocharger's compressor housing to the wastegate pressure sensor?

If that's the case, then your turbocharger is faulty. If you drive without this hose, the boost pressure would no longer be limited, meaning it would continuously increase until the turbocharger self-destructs due to over-revving.
If you only reached 0.5 bar of boost, the wastegate is likely stuck in the open position.

Or was it the hose to the fuel injection pump?
That would only have the effect of disabling the pressure-dependent enrichment function. The maximum boost pressure would remain unaffected.

Regards,
Jens.

Hello Euro,
Which hose did you disconnect exactly?
The one that runs from the turbocharger's compressor housing to the wastegate pressure sensor?
Regards,
Jens

Hello Jens,
I disconnected the hose from the compressor housing to the wastegate pressure sensor for a test drive once (this was when I was only producing a maximum of 0.25 bar of boost, so before I adjusted the boost screw further). It didn't make any difference.
You wrote earlier that, in your opinion, there were no chargers that had a hose in that location, which is why you speculated that someone might have tampered with it. I've now looked at pictures of various chargers for the G2, and almost all of them have a metal pipe at the top of the compressor housing that transitions into a rubber hose about halfway along its length; that's exactly the hose that I had detached from the device. So, it seems to be original equipment.

But there's no question that the car has been 'modified,' after all, it was originally a GTI and is now a GTD with everything that the VW accessory shelf for the G2 had to offer .

I don't think your conclusion that '...driving without the pressure hose means a faulty turbocharger because there's still not enough boost' is necessarily correct. Could it not also be due to the injection quantity? I mean, if the turbocharger is faulty, the car should produce a lot of soot in all load ranges (i.e., in the areas where the turbocharger normally operates), right?
As I said, I've never seen any black smoke (regardless of how much the fuel screw is turned) when driving at full throttle. This means there's more air available than is needed for combustion, which implies that the turbocharger is working.

Regards,
euro

euro wrote:

You wrote earlier that, in your opinion, there were no chargers that had a hose in that location, and therefore you speculated that someone might have been tampering with it.

I was mistaken because I had the KKK turbocharger in mind. Garrett turbochargers actually have a rubber hose as standard equipment in that area.

Quote:

I don't think your conclusion that "...driving without the pressure hose means a faulty charger because there's still too little charging current" is necessarily correct.

I think so. Without the line, the wastegate is out of function, and the turbo is therefore unregulated. Without regulation, the turbo would go into self-destruction (or, in this case, the pressure relief valve on the intake manifold would prevent a turbo disaster). Since the boost pressure didn't increase during the test drive and the pressure relief valve didn't have to do anything, it is defective.

Quote:

Could it also be due to the amount of fuel being injected?

As you described it: No.

Regards,
Jens.

Quote:

In this case, the pressure relief valve on the intake manifold would prevent a turbocharger catastrophic failure

.

Perhaps it also prevents the LD (low-pressure) from rising above 0.5 bar because it opens too early...

So, I had already completely replaced the pressure relief valve (with one from a Jetta), but that wasn't the problem either.

Yesterday, I had some more time to check a few things.
I disconnected the rod from the pressure sensor to the wastegate and manually operated the lever on the wastegate (that small metal plate with the pin where the rod is attached). I could move it very easily, but I didn't hear the 'popping' sound that many people describe when it's in the 'closed' position.
The sound was similar to the noise you'd hear when tightening a nut onto a bolt by hand, and then giving it a little extra turn.
I'm now very curious to know exactly how the mechanism for opening the flap works, what the flap is made of, and what could potentially go wrong with it.
Can you actually see the wastegate on Garrett turbochargers if you unscrew the exhaust pipe bend? Does anyone have any pictures?

Also, yesterday it was already late when I wanted to re-install the rod. Since I couldn't slide it over the small pin in its original position, I unscrewed the rod slightly – it has a thread, you see – so that I could connect it without any pre-tension.
Today, during my usual commute to work, the lambda value (LD) was not the usual 0.5, but only 0.45, and it was producing more soot.

I'm not quite at my best right now, I was up late yesterday . But can anyone of you make use of this information?

euro

Okay, so I couldn't move the rod manually on my extended loader; I had to use pliers. The loader itself was in perfect condition, so it wasn't broken.
I also have a picture showing the flap as it opens.

The EVL is faulty because the spring is broken, causing it to open even with a very low LD (light intensity).


Someone might have tried to completely disconnect the Wasgate, perhaps by disconnecting the hose so that the Wasgate no longer receives any signals!