ASZ extreme performance issues

Hello to the Dieselschrauber community...

I'm now completely at a loss with my TDI. I've checked all the tips I found in the forum as much as possible, but I haven't been able to find the cause of my performance problem yet.

Short description of the vehicle: Skoda Fabia RS 130 hp PD TDI (MKB ASZ), now converted to ARL Turbo (but this doesn't have anything to do with the problem), actually runs with a Pbox... however, this has been removed for the measurements etc. attached below in order to be able to compare it better... also, the larger intake from the Ibiza Cupra TDI is installed... Current mileage is approximately 100,400 km (problem has been present for over 20,000 km )

Problem Description:
The vehicle pulls very well in the first 3 gears, reaching the red RPM range...
In the 4th, 5th, and 6th gears (and sometimes even in the 3rd gear), the red speed range is often not reached (the tachometer simply remains still). However, it is not always possible to state definitively that the engine "hangs" at the same speed. In most cases, it is around 3,500 or 4,000 1/min.

checked or exchanged:
Air Filter
Diesel filter
LMM
AGR
Alurohr replaced between LMM + Turbo
Turbo (Conversion to ARL Turbo)
Valve block for low pressure or Pump pressure control replaced, hoses inspected.
{SENSOR TYPE}: Pressure/Temperature sensor located on the LLK (Low-Level Control) unit - Replacement required.
Catalytic converter not rattling...therefore, it should be functioning normally.
Otherwise, there should be no unusual constrictions etc. in the exhaust system.
The drainpipe was removed and thoroughly cleaned.

Here you can find the 2 log files... the first one is probably the more interesting one:

http://www.donsilencioso.de/Performance/

In addition, here is a diagram of my boost pressure trend in the 4th gear. Gang




I hope you still have a solution...I have no idea what I can do anymore...

Greetings

Christian

Hi Christian,

The load pressure control is working perfectly
The question is simply, why does the control unit reduce the boost pressure at 3200 rpm?

What does the ambient pressure in measurement block 10 (keyword: protection of the motor from overspeed) do?

What are all the temperatures during the LD (Diesel, Intake Air, Coolant) going to the basement?

Greetings, Rainer
PS: Instead of the PBox, there would definitely be more soot-free performance...

Rainer K. wrote:

Hi Christian, The load pressure control is working perfectly The question is simply, why does the control unit reduce the boost pressure at 3200 rpm? What does the ambient pressure in measurement block 10 (keyword: protection of the motor from overspeed) do? What are all the temperatures during the LD (Diesel, Intake Air, Coolant) going to the basement? Greetings, Rainer PS: Instead of the PBox, there would definitely be more soot-free performance...

I haven't logged Block 10 yet, but I'll catch up on it.

"I've also logged the temperatures in the other file...the fuel temperature + intake air temperature seem a bit higher to me...but the coolant is definitely in the normal (realistic) range under full load...I'm going to quickly check again and see what values he's showing as "cold" now...that should be the ambient temperature for the intake air, coolant, and fuel."

on which value in block 10 should I pay close attention?

Instead of the Pbox, a chip is planned to utilize the larger turbo , but first, the problem must be solved...otherwise, it wouldn't make sense.

EDIT: So, the engine is still too hot to accurately assess the temperatures...they are all still quite high...Coolant is at 57 degrees and fuel is at 49 degrees... (Also, the intake air temperature is also in this range...shouldn't it be cooling down faster?)

Rainer K. wrote:

The question is simply, why does the control unit reduce the boost pressure at 3200 rpm?

Hello,

That seems to be the key point to me as well!

The LD curve of the ASZ, however, looks "somewhat different" than the target profile in the graph, namely from 2350 mbar to approximately 3500 rpm, 2300 mbar @ 4000 rpm, and then further decreasing.

In the series trim (!), my ASZ-Polo also slightly reduced the LD target, due to excessively high LLT: but this was a difference of magnitudes, approximately 0.1 bar less, starting around 3500 rpm, with an LLT of approximately 80°C, I believe.

Since the LLT in Christian's Logs rises significantly above 90°C, this might be the cause (I don't know from personal experience how the EDC normally behaves at such high LLT values, but I improved the effect of my LLK well in advance -> see LLK photo in my signature).
Does your performance decrease the more it's hot outside?

Is it possible that your LLK is completely messed up / built in such a way that hardly any air can get through or behind it (tuning front spoiler, incorrect spoiler grid . . .?)

Or should the radical LD reduction be considered an emergency -> error memory??

ulf wrote:

The question is simply, why does the control unit reduce the boost pressure at 3200 rpm? Rainer K. wrote: Hello, That seems to be the key point to me as well! The LD curve of the ASZ, however, looks "somewhat different" than the target profile in the graph, namely from 2350 mbar to approximately 3500 rpm, 2300 mbar @ 4000 rpm, and then further decreasing. In the series trim (!), my ASZ-Polo also slightly reduced the LD target, due to excessively high LLT: but this was a difference of magnitudes, approximately 0.1 bar less, starting around 3500 rpm, with an LLT of approximately 80°C, I believe. Since the LLT in Christian's Logs rises significantly above 90°C, this might be the cause (I don't know from personal experience how the EDC normally behaves at such high LLT values, but I improved the effect of my LLK well in advance -> see LLK photo in my signature). Does your performance decrease the more it's hot outside? Is it possible that your LLK is completely messed up / built in such a way that hardly any air can get through or behind it (tuning front spoiler, incorrect spoiler grid . . .?) Or should the radical LD reduction be considered an emergency -> error memory??

I have now logged the measurement blocks. They can be found under the link above (recognizable by the date 14_06 at the end of the file).

The LLK is actually quite clean...at least that's what I remember from the last time I looked at it...I'll check it again though...the air duct leading to the LLK has been removed because it was broken after a minor accident (but it was at least 60,000 km ago!), after I couldn't notice any difference, I didn't order a new one at the time...I also checked the LLK for visible damage occasionally, but I didn't find any.

The error log initially showed the LLM output at the very beginning... Since then, nothing else has been found in the log.

and right...the warmer (yesterday was really intense, not so much this morning) the worse the whole situation is...in the extreme case, only 160 on the highway

Before starting today morning, I re-examined Block 7... the measurements should be within an acceptable range, approximately 2-3 degrees above the ambient temperature.

Regarding your LLK... what does that cost?... Would it make sense to test out expanding the {NEBLER} (which I also have in front of the LLK)?

By the way... I just remembered... the problem occurred in stages... that is, it first only appeared at temperatures >32 degrees... then it "worsened" until I even had problems at +5 degrees... perhaps this also indicates a specific component?

If the intake air temperature is the determining factor for reducing the boost pressure, why does it only occur in high gears?

It would be interesting to see a complete log from acceleration phase 1 to phase 4 or 5.
Here, we should check if the air intake temperature is actually the determining factor. Ideally, it should be consistent across all gears if the air intake temperature is above 90°C.

If my MSG goes into emergency mode, I now have 0.5 bar of boost pressure, similar to what the PD has, but I don't know if there's a 'temporary' emergency mode. So, he would have to keep the ignition off for as long as possible, and always have a low level of boost pressure.

Why don't you just take the fog lights out and see what happens?
Is it then less, does it really depend on cooling...

Best regards,
Jochen

Jochen_145 wrote:

If the intake air temperature is the determining factor for reducing the boost pressure, why does it only occur in high gears? It would be interesting to see a complete log from acceleration phase 1 to phase 4 or 5. Here, we should check if the air intake temperature is actually the determining factor. Ideally, it should be consistent across all gears if the air intake temperature is above 90°C.

I suspect that he may not be able to shift gears effectively in the lower gears, and therefore the issue only occurs in the 4th, 5th, and 6th gears where the engine needs more time to rev up... I also suspect that there is an electronic fault... because the problem only occurs intermittently... and I'm also remembering that sometimes it happens in bursts... meaning I'm accelerating, there's a loss of power, then the power returns, and then there's another loss of power...

It would be best if I re-logged the logs for gears 7, 8, and 10, from 0 to 4, while accelerating through each gear.

Jochen 145 wrote:

If the intake air temperature were the determining factor for reducing the boost pressure, why does it only occur in high gears?

Because the LLT has a certain heat buffering effect. In the lower passages, the high LD is not maintained for such a long period of time that it completely "overheats" the system, and the LLT reaches critical values at its output.

cupra-turbo wrote:

skirts etc. are part of the series... but the air duct leading to the LLK (Left Lateral Link) has been removed because it was defective after a minor accident (but it happened at least 60,000 km ago!), after I couldn't notice any difference, I didn't order a new one at the time... I also checked the LLK for visible damage occasionally, but I didn't find any...

Take a good look at it (from the front and back!), to see if the fins might be clogged with oil and dust, as a result of a small crack after the accident.

The air duct definitely belongs to the LLK!
A comparison of LLT log data with and without it (full throttle in 4th gear up to 4000 rpm) will show you why.

Quote:

This morning before starting, I re-examined Block 7...the measurements should be within an acceptable range, approximately 2-3 degrees above the ambient temperature.

Then the donor should be okay.

Quote:

and right... the warmer it gets (yesterday was really bad, not so bad this morning) the worse the whole situation is... in the extreme case, only 160 on the AB By the way... I just remembered... the problem occurred in stages... that is, it first only appeared at temperatures >32 degrees... then it "worsened" until I even had problems at +5 degrees... perhaps this also indicates a specific component?

So, apparently, it's a gradually increasing protective response to excessive LLT's.
Could this be caused by increasing external contamination of the LLK (see above -> Oil film)?
With this information, I now believe that the combination of the nozzle + no air channel + dirt in the outer LLK lamellae is the cause of your problems.
Remove the Nebler, verschandeln the air duct, thoroughly verschandeln the LLK - and the Fabia is running again, I almost dare to say... provided the LLK is intact.

Quote:

Does it make sense to test-install the Nebbler (which I already have for the LLK) first?

Definitely for the Polo, and probably also for the Fabia.
However, it could be that the few K reduction in the LLT only slightly (or imperceptibly) alleviates the problem -> see above.

Quote:

to your LLM...what does that cost?...

It's a custom-made, one-of-a-kind item, so the price is negotiable with the specific radiator manufacturer.
However, if you're not doing extreme tuning, the stock LLK is perfectly adequate - with a sealed cooling air duct, and if it gets really hot, without a fogger.
If you cut an exhaust hole in the radiator housing behind the LLK (starting from the back-bottom edge, approximately 10 cm high and 5 cm forward, approximately 15 cm wide) so that the spray water from the tire no longer hits the LLK, it will cool down a few more degrees.

@ Ulf

then I'll try something out tonight, tinker around, clean + cut

and then let's see if it's better

I'll try to put the air control system back together and reinstall it...

I will get back to you tonight/tomorrow morning at the latest.

cupra-turbo wrote:

@I'm going to try to put the air control system back together and reinstall it...

That should be enough, perhaps a few meters of packing tape, if the puzzle doesn't consist of too many small pieces.
Only if the brackets on the LLK or the tunnel are broken, it becomes a problem.

Otherwise: Density is more important than aesthetics!

Good luck

cupra-turbo wrote:

@ Ulf then I'll try something out tonight, tinker around, clean + cut and then let's see if it's better I'll try to put the air control system back together and reinstall it... I will get back to you tonight/tomorrow morning at the latest, if necessary.

You can also use the rear bumper grille from an Audi TT. However, you will need to modify the bumper shell for this. Cut out the grille with a generous border and attach it to your shell, for example, by welding it in, and if necessary, seal it with silicone. This at least eliminates the risk of dirt being transported into the LLK grid through the spray water.

If I remember correctly, Rainer K.'s self-experiment with holes in the shell on the A3 wasn't particularly successful.

@Ulf:

A colleague with a 96 kW Ibiza from 2005 had problems with a "fail-safe" mode this weekend. After about 3 hours of "maximum" acceleration, the car suddenly only reached 120 km/h, and after a restart, everything was normal again. Unfortunately, no error code was recorded the next day. The oil was near the min. marking, otherwise everything appeared normal.

The vehicle is completely stock, except for a mass air flow adaptation and a Cupra-style spoiler. Could the emergency shutdown be related to the excessively high LLT, even if no emergency shutdown error was recorded?

Roger wrote:

You can also use the rear bumper grille from an Audi TT. However, you will need to modify the bumper shell for this. Cut out the grille with a generous border and attach it to your shell, for example, by welding it in, and if necessary, seal it with silicone. This at least eliminates the risk of dirt being transported into the LLK grid through the spray water. If I remember correctly, Rainer K.'s self-experiment with holes in the shell on the A3 wasn't particularly successful.

I am aware of the rejection barrier, but thank you for the tip

I also read the "report" and, as a result, I've decided to remain calm... but I think it can only get better from here

It's possible that the LLT was too high, which caused the system to go into emergency mode...it seems to be the case for me as well...I don't have any errors in my memory either...

Roger wrote:

A colleague with a 96 kW Ibiza from 2005 has experienced problems with the "emergency mode" this weekend. After about 3 hours of "maximum" right foot pressure, the car suddenly only reached 120 km/h, and after a restart, everything was normal again. Unfortunately, no error code was recorded the following day. The oil was near the min. marking, otherwise everything appeared normal. The vehicle is completely stock, except for a mass air flow adaptation and a Cupra-style spoiler. Could the emergency shutdown be related to the excessively high LLT, even if no emergency shutdown error was recorded?

Good question... I haven't been able to directly check for a fault code in the memory after a fault code has occurred before.

The LLT usually drops to non-critical values within a few seconds under full load or partial load, so that when accelerating, at least temporarily, the full power should be available. sofern the LD reduction dependent on the LLT does not have a longer "memory" (pure speculation!).

I'm trying out a few things with my Polo, but intentionally pushing it to the brink of a failure due to the limitations of the LLT isn't on my to-do list

Okay, I'm sorry, but for your colleague, I can only recommend VAGCOM

If you cut an exhaust hole in the Radhausschale behind the LLK (starting from the back-bottom edge, approximately 10 cm high and 5 cm forward, approximately 15 cm wide) so that the spray from the tire no longer hits the LLK, it will cool down a few more degrees.

Why should water be a problem?
If you drive slowly, the water won't reach the radiator. If you drive fast, due to aerodynamics, there will be a vacuum in the front wheel arch, which is now flushed out by the overpressure from the intake of the cooling system. Therefore, very little water gets there.
This is actually a shame, because the spray water cooling is also installed by others as an additional feature

I think a stone protection system within a frame (aluminum, available at Lidl) is sufficient.

Regarding size, I'm curious to see how it turns out. I've now made a significantly larger cut. Something like the entire area of the cooler. I will now measure the temperature difference using a Type-K thermocouple (thermocouple placed before the LLK and before the Stauklappe).
Then you can easily remove and reattach different areas.
I am certain that this, in contrast to Rainer's measurements, has an impact.

Best regards,
Jochen

Ulf wrote:

Normally, the LLT will drop to non-critical values within a few seconds under full load or partial load, so that when accelerating, at least temporarily, the full power should be available. This is only true if the LD reduction dependent on the LLT does not have a longer "memory" (pure speculation!). I'm trying out a few things with my Polo, but intentionally pushing it to the brink of a failure due to the limitations of the LLT isn't on my to-do list Okay, I'm sorry, but for your colleague, I can only recommend VAGCOM

Hello Ulf,

The effect persisted even at low speeds - and it also didn't allow for fast acceleration . Therefore, it seems clear that it was definitely an emergency situation.
No one here wants a collapse . I only found the missing entry in the memory suspicious, and otherwise, everything else seemed to fit the topic.

He has VAG-Com, of course - the interface is even available from here in the shop . But the colleague only got it out the next day, just returned from a long flight, and hadn't had any intention of doing so yet. I recommended that he bring the "Lappis" along for the next highway trip as a precaution.

I have already carefully examined my ASZ, but I have never been able to provoke a failsafe mode...

Jochen_145 wrote:

Why is water a problem? If you drive slowly, the water won't reach the radiator. If you drive fast, due to aerodynamics, there will be a vacuum in the front wheel arch, which is now flushed out by the overpressure from the intake of the cooling system. Therefore, very little water gets there.

Hi Jochen,

Water (and dirt) fly tangentially away from the tire, even when moving diagonally forward and downward: this can be clearly seen by examining the dirt tracks on the entire inner side of the Radha shell.
Do you think that this rapid-moving [object] can be so significantly diverted from its course by a relatively small amount of hot exhaust fumes from the [system], that it suddenly veers around the [system]?

Why do manufacturers install intricately shaped fins behind the SMIC-bred, high-performance engines in the radiator shells, instead of leaving the hole completely open?
What could be the reason, besides preventing dust from the cooling system?

*) Blow hard into your hand, then hold a LLK (Liquid Cooling Kit) in front of your hand - and be amazed at what residual airflow remains behind the cooling unit

Quote:

Now I've made a much larger cut. Approximately the entire surface area of the cooler.

Then take a look at a few hundred kilometers of water (preferably with some mud ) from behind

Quote:

I will now measure the temperature difference using a Type-K thermocouple (thermocouple placed before the LLK and before the Stauklappe). Then you can easily remove and reattach different areas. I am confident that this, in contrast to Rainer's measurements, has an impact

. Please let us know the results .