Once again, poor performance, 1.4 TSI (103kW / 140PS), resolved.

Good day,

Today, I was troubleshooting a Golf V Plus 1.4 TSI with 103kW Twin-Charger.
Now I see that this forum has been expanded to include the title TSI , which I am very pleased about.

Technical Data of the Problem Child:
Golf V Plus, First Year of Production 07
1.4 TSI 103kW / 140PS as Twin Charger
Error: No performance above 3000 RPM
A noticeable fluctuation or "wobbling" in the engine speed around 1800 RPM seems to indicate that the control of the compressor's air valve may be starting to become unstable.
The undulating acceleration, also known as "hunting," is sometimes even visible on the tachometer. For example, it occurs at 100 km/h in 6th gear at approximately 2200 rpm...
(Wavy acceleration is probably an inaccurate description, as the oscillation occurs more in the partial load range.)

Okay, now I've performed a VCDS diagnostic and, as you can see, the target boost pressure is significantly higher than the actual boost pressure starting around 3400 RPM.
Sorry, I'm also expressing myself incorrectly. The "loaded pressure" cannot maintain the required pressure. The pressure exerted is not unusually variable.

The control of the valve (N75?) is usually 99.6, which means full power.

Attached is a drawing of the loading pressure track and motor images.

My current problem is that I still don't have a clear understanding of the valves. Since it seems there are 2 N75 valves, which one is being controlled?
A general overview of TSI technology can be found in the self-study program VW SSP 359 (simply Google it).

N75 (Turbo Pressure Can) Part Number: 06F 906 283 <- Currently Installed
(allegedly replaced by the following: 03C 906 283 A)

N75 ?? TN: 03C 906 283
(was regulates it? There is a small black pressure vessel attached to it, but where does it lead? It is common.

N249 TN: 03C 145 710 A (new version 03C 145 710 D)
(It is likely 03C 145 710 A, but I have not yet verified it. Source: new TN http://www.golfv.de/150975-abschaltventil-turbolader-n249-mech-fehler-selbst-getauscht-in-20-minuten.html)

Images are attached below to illustrate the loading pressure path, without the LLK.

As I now see it, both the N75 and the N249 could be faulty. It's even possible that the bypass valve on the compressor isn't opening... and therefore the turbo isn't getting any air?

How can I best check without ordering any unnecessary items?

lg Apple

Hi,
A few initial observations. There is only one N75, which is used for the controlled opening of the wastegate on the turbocharger.
edit: The N249 is used to dampen the boost pressure control when the throttle valve is closed (****)
Since the problem occurs even at partial loads, I would start by investigating the behavior of the Roots blower's boost pressure (G5839) and the boost pressure (G319). (Please excuse me if I'm referring to the supercharger as a Roots blower )
hg
Herbert

Hi

Well-behaved acceleration is a hot topic for the 122 PS (only turbo) TSI engine.
There, the wastegate shaft of the Mitsubishi turbo gets jammed, and there's also a TPI, which requires the turbo to be partially replaced.

Is your turbo in good condition, meaning, is the wastegate definitely NOT stuck?

m;

Supplementary Information:
Edit: I also want to point out that the wavy/pulsating motion is not my main problem, but rather that the turbocharger is not building up boost pressure. The other one will certainly be related to that.
So, the wastegate valve is movable, and the pressure sensor provides approximately 1.5, maybe even 2 cm of travel. The can is pressurized and exerts force.
Turbocharger is, as far as I know, a KKK, therefore not a Mitsubishi.
MKB: BMY (according to VIN)

Herbert wrote:

There is only one N75, which is used for the controlled opening of the wastegate on the turbocharger. edit: The N249 is used to dampen the boost pressure control when the throttle valve is closed (****) .... Partial load area occurs.. Start the Roots blower (G5839) and the loading pressure (G319). Hi Herbert

What then controls the second magnetic valve? Is it the small black ink cartridge located behind the engine?
Does the N249 also not serve as a bypass for the compressor air? Or does the air constantly run through the turbo? Can I simply remove the N249, put a plastic bag over it and install it so that I can turn the turbo one (and only one!) time to see if it generates pressure above the 3400 rpm mark? This way, I could rule out the N249 as the culprit. Exposing...

According to VW, there is an area where the Roots blower (compressor) and turbo overlap, therefore I assume that the error is not actually due to the Roots blower, but also due to an unwanted feedback loop behavior due to the lack of turbo pressure. I found the sensors G5839 and G319 in the measurements. Are there any online resources where these sensors are located? For understanding.

dieselmartin wrote:

Is your turbo in good condition, meaning, is the wastegate definitely NOT stuck? m;

Yes, the wastegate valve is movable, and I checked it directly on the can using a hand pump. Also, the turbine shaft is still within the green range, allowing for play and smooth operation. Acceleration is only weak, but not directly wavy; the flickering occurs in the partial load range.

Thank you for the previous responses

Hi,
My recommendation is to consult a repair manual when continuing to troubleshoot. This makes the process easier, as individual troubleshooting steps are described with target values. This also eliminates questions about parts that you can see in the engine, but the reader here, of course, cannot. You can find the RLF at Erwin's.

Regardless, we can first check if the valves, flaps, etc. for the air flow are mechanically functioning correctly. Let's start with the wastegate. As you mentioned, it doesn't get stuck, but is movable. Does the pressure regulator (with its membrane and spring) also keep it closed when the engine is idling? The function of the wastegate can be found here (should also apply to the TSI wastegate): /viewtopic.php?t=3101
hg
Herbert

Quote:

Regardless, we can first check if the valves, flaps, etc., which control the air flow, are functioning mechanically correctly.

There, that's where I would start. The control valve J808, which regulates the air flow for the compressor/turbo, should be found in the measurement blocks.

Reliably shut off the compressor from the air flow at 3500 RPM, and continue searching for the turbo.

Then, one must ensure that the air circulation valve closes securely.

Is everything OK, does that basically just leave the turbocharger including? Wastegate as a source of error for missing boost pressure.

Autoservice wrote:

There, that's where I would start. The control valve J808, which regulates the air flow for the compressor/turbo, should be found in the measurement blocks. "It reliably cuts off the compressor's airflow at 3500 RPM, and further in the direction of the turbo."

I would like to have this valve mechanically inspected. How is it controlled?
Regarding the vacuum and pressure gauge (?), this might be the "second N75" where the "TSI Engine Complete" is located at the top of the image.

Autoservice wrote:

Then, one must ensure that the air circulation valve closes securely.

see N249 below.

Current Status:
N75 (Turbo Pressure Can) Part Number: 06F 906 283 <- Currently Installed
is now being replaced because it's not working...
What is the new part number for the upgraded version?
Have in div. I've been reading forums that there are now 03C 906 283 A and B parts.

I thoroughly examined the N75 yesterday, and the result was TOTAL FAILURE. It doesn't work at all and doesn't switch on. The driver of the Golf, yes, it's always been a problem, especially for a 140hp engine, meaning since over 150,000 km...

N75 ?? TN: 03C 906 283 is new
I would like to know what this valve with the small plastic pressure canister controls? Does anyone have any idea? Is it maybe the J808 valve?

N249 TN: 03C 145 710 A is already the new version 03C 145 710 D
Works perfectly, tested.

Hi,
You're saying that you're reading SSP 359 above?
- The main valve J808 is controlled by the MSG to regulate the loading by the compressor. So, there's a stepper motor, but no pneumatic control system;
- There is only one N75, which is used for overboost of the wastegate control. The pressure control via the pressure gauge - wastegate control system is therefore being over-controlled;
hg
Herbert

Herbert wrote:

You're saying that you're reading SSP 359 above?

Yes, I also found the J808, but I don't want to create another separate post just for that, it's really annoying that you can only edit for 60 minutes!

Herbert wrote:

- The main valve J808 is controlled by the MSG to regulate the loading by the compressor. So, there's a stepper motor, but no pneumatic control system;

And what controls the second solenoid, which I can't call an N75 (but actually functions the same way), because you correct me every time? It controls a plastic pressure can with vacuum, and I can't find it in SSP 359...
I have asked this question numerous times, yet I have not received an answer.


The performance issue has been resolved!
N75 was dead and has been replaced,
Original Part Number: 06F 906 283 F <- Factory Fitted
New part number: 03C 906 283 B
if you call VW, they will actually sell you the old part 06F 906 283 F! Therefore, be sure to search for the part using the frame number, then you will find the new one... ******* the system...
The cost is currently only 40.88€, but it will likely become more expensive


The issue with the jerking is still present, so we are now replacing all the ignition coils and spark plugs (again). And see if anything changes then.
Are there any other suggestions? VCDS documentation increasingly shows ignition misfires, particularly on cylinder 1 and 4, sometimes also clustered on 3, and occasionally fewer on 2. Is this roughly normal? The test course was only 5 km long.
This time, I am consistently choosing BERU over OEM due to poor experiences.

Best regards, Apple

Quote:

The issue with the shaking still persists, so we are now replacing all the ignition coils and spark plugs (again).

Start with the spark plugs - otherwise, you'll never know if it was the plugs or the ignition coil.

First of all, it's good that the error is gone.
But to your question:

Quote:

And what does the second solenoid control that I can't call N75 (but which actually functions the same way), because you correct me every time? It controls a plastic pressure can using vacuum, and I don't find it in SSP 359... I have asked this question numerous times, yet I have not received an answer.

The first image in your initial post has low resolution, so that you can't actually see what you mean. Nevertheless, the upper part should either be the actuator module for the mechanical charger or the valve for the variable valve control. The lower one is the boost control valve.
Are the two "valves" actually the same? Where do the connections from the valve in your first image above go?
hg
Herbert

Good day,

Okay, so now I've replaced all 4 candles -> no improvement. The idle is also uneven.
then ignition coil 1 and 4 ----------------------> no improvement, idle also uneven
now also ignition coils 2 and 3 ----> no improvement, idle is also uneven

"The car runs like a (expensive) bag of nuts, the engine is already idling quite intensely in the engine bearings, and it does the same thing in partial load range, for example at 90 km/h."
It's so intense, this "vibration" that the car has now become unmanageable....
VW offers 3k for the vehicle... BJ07

I have observed that the shaking has disappeared for approximately 15 seconds after I performed a coupling and gave a few short bursts of gas (up to 1500 umin). Afterwards, the engine returned to idle and remained stable for the aforementioned 15 seconds until the shaking stopped. (When engaging, the compressor switches on and ensures forced ventilation) There is no shaking at full load (Note - Subjective).
I have also moved all the wires to the ignition coil on the running engine and tried to eliminate any possible loose connections.

I have now inquired again about the FSI engine and its problems, and I came across the following: http://www.youtube.com/watch?v=R1T18Zwy7QU

Now I plan to do this myself...
Do you have any further suggestions, ideas, or recommendations?

Best regards

Hi,
Now you're working your way from the air intake control, through the ignition system, to the fuel injection valves. I would start by looking for the basic things.
- You've replaced the spark plugs and ignition coils. Were there any noticeable features on the old candles?
- is the ignition timing stable?
- are all sensor values plausible, e.g., temperature values. I had a case with an Audi B3 where a faulty temperature sensor led to over-fueling.
- Fuel pressure and injection quantities are correct?
hg
Herbert

Herbert wrote:

- You've replaced the spark plugs and ignition coils. Were there any noticeable features on the old candles? - is the ignition timing stable? - are all sensor values plausible, e.g., temperature values. I had a case with an Audi B3 where a faulty temperature sensor led to over-fueling. - Fuel pressure and injection quantities are correct?

Okay, I've finally found the solution! *happy* And the car is no longer stuttering.

First, regarding the questions you asked:
- The spark plugs are very thin around the electrodes (my father initially said "wow, completely burned out," but the new ones also look the same). Definitely in perfect condition, at least visually.
- ?? How can one check the ignition timing for stability? It can't be done by attaching a sensor to the ignition wires / coil / amplifier, can it?
Did you know about the basic setting mode in the Golf 3? Do you mean something like that?
- Sensor values are plausible
- I also logged the high-pressure fuel pressure, and the setpoint and actual values are very well aligned (subjective, I haven't seen any other comparable values!)

Okay, now to my solution:
[I am mentioning this solely for completeness, to ensure that potentially implausible sensor readings may have also contributed to the poor engine performance]

One day, the engine control light suddenly came on. After reading the error codes, the result was "Sensor signal implausible (air pressure (G71) / (F96) & intake air temperature (G42))." A look under the hood revealed that a cable had broken, which had already been patched by a VW workshop, but so poorly that it had broken behind that point. Okay, new pin inserted with cable, and soldered a bit further behind the click point, and then preserved. -> Error marked as resolved

I bought this set with a pressure pump and spray nozzle. (see post above)
Also, Liquid Moly - Ventil Sauber, 150ml pro Dose, auf Amazon Marketplace für 3,7€ pro Dose + 3,9€ Versand... Ich habe direkt ein paar Dosen bestellt.


Now I have removed the sensor at the back of the spray nozzle in the intake channel. (For this, I also had to remove a small hose to reach the sensor). The sensor was secured with 2 Torx screws and could be easily removed with standard wrenches.

Now I have completed the following steps:
- Nozzle instead of sensor installed.
- Sensor tip inserted into gasoline for cleaning.
- Sensor dried and contaminated, but the cable harness is in an unmounted state.
- Reattach the small hose that was in the way when the sensor was removed.
- The engine started and the accelerator pedal was held down firmly, maintaining around 2000 RPM (it's better not to have anyone in the car, as they would instinctively press the accelerator further when the engine speed increased, which I didn't want!)
- Now, after injecting with the high-pressure pump for about 5 seconds, wait until the engine speed has normalized again (therefore, no one needs to be at the accelerator pedal)
- waited a few seconds after feeling the sensation when the engine speed returned to normal
- Approximately 5 more seconds injected...
- Approximately 50-80ml of remaining stock
- Now, permanently inject, so that the RPM drops, and then directly turn off the engine and continue injecting until we reach 0ml.
- Now, a minimum of 30 minutes break (this allows the mixture to settle and dissolve the dirt, and also cools the cat down...)
- Start the engine, give it gas, and possibly take a short drive (which can be a bit cumbersome due to the pump and cables in the engine compartment.)
- Repeat the entire process several times, for me, a total of 4 times, so approximately 1 liter of gasoline and 200ml of Liquid Moly - Valve Clean.



Approximately 250ml gasoline and 50ml of cleaner per cycle!



Okay, now the engine has been running smoothly for a week!
The idea behind this cleaning method is that the intake valves in direct injection engines do not self-verschandeln like in intake manifold injection! Audi (therefore, VAG) has probably learned from this and builds the 1.8 TFSI in 3. Generation (starting from 2010/11) now with 8 injection nozzles, both direct and indirect injection (under the guise of efficiency).

If you need a pump with a nozzle that I purchased, you can contact other enthusiasts who may be willing to donate the pump.


Finally, a moderator could change the title to: "Resolved: No Performance & Jerky / Irregular Engine Running, 1.4 TSI (103kW / 140PS)"

Thank you for the feedback!