10c Tuning für Anfänger HowTo? | Posts 16+

Hello Ulf,

What exactly does 'lower resistance' mean? Does the resistance value need to be lower when the diodes are installed, or how should this be understood?
My friend tested the potentiometer setup today at a company that specializes in 1Z models. It immediately triggered the limp-home mode upon activation. I think I'll buy a second rear window defroster switch and connect everything to that. I don't have seat heaters, so I have space for it. A non-original switch just doesn't look right in a Passat...

best regards
Ronny.

Hello everyone,

How about a micro-switch located under the accelerator pedal that only activates the tuning when the accelerator is fully depressed?

I would explain the working principle of diodes as follows:
Apparently, there's a coil inside the pump that generates a signal related to the fuel injection amount. It's reasonable to assume that the frequency of this signal increases with the pump's rotational speed, and the amplitude increases with the fuel injection amount. The actual injection amount is then derived from the amplitude of the signal. If you simply add a resistor in parallel, it changes the entire signal. A diode, on the other hand, doesn't have a linear resistance. It only becomes conductive when the voltage increases (0.5 - 0.6 volts for silicon diodes like the 1N4148). Therefore, the signal isn't completely altered, but only its 'peaks' are affected.
Fine-tuning might be achieved by experimenting with diodes that have different breakdown voltages and characteristics (e.g., germanium diodes at 0.4 volts, Schottky diodes at approximately 0.3 volts, red LEDs at 1.3 - 1.6 volts, etc.).

Has anyone ever measured this signal with an oscilloscope? I don't have one myself, and I don't know anyone who does. It would be interesting to see.

I can also imagine that interesting effects could be achieved by using capacitors or coils connected in parallel, such as tuning that only works within certain speed ranges.
So far...
Regards,

Eike.

PS: Ulf, do you know anything about power steering pumps? I need to replace one.

Hi.

@ Ronny:
Yes, the resistance value needs to be lower; previously, values around 200-300 ohms (instead of approximately 800 ohms) have been mentioned.

@eike:
Servopumps are not my area of expertise --> please contact other colleagues.

Quote:

How about a micro-switch under the accelerator pedal that only activates the tuning when the accelerator is fully pressed?

A seemingly appealing idea, but if you activate the tuning mode at already high engine load (i.e., almost full throttle), you'll experience a noticeable jolt, especially at speeds below approximately 100 km/h in the lower gears, which probably won't feel very pleasant.
Therefore, I would tend to recommend a manual switch, but ultimately, everyone has to decide for themselves .

Quote:

I would explain the operating principle of diodes as follows: Apparently, there is a coil inside the pump that generates a signal based on the fuel injection amount. It is likely that the frequency of this signal increases with the pump speed, and the amplitude increases with the fuel injection amount. The actual fuel injection amount is then apparently derived from the amplitude of the signal.

To the best of my knowledge and based on my attempts, this is only partially true.
The throttle body consists of a fixed inductance and a variable inductance (which varies depending on the slider position). The engine computer compares their ratio and derives a voltage from it, which is a measure of the slider position, i.e., the amount of fuel injected per cycle.
The device, incidentally does not function as a transformer, because no (significant) voltages can be induced between the two coils.
The measurement frequency should always be 10 kHz, regardless of the pump speed. However, the amplitude of the measurement voltage may be increased with the speed, which could explain the effect of the diodes .


If you only connect a resistor in parallel, it changes the entire signal. A diode, on the other hand, does not have a linear resistance. It only becomes conductive with increasing voltage (0.5 - 0.6 volts for silicon diodes like 1N4148). Therefore, the signal is not completely changed, but only its "peaks".

Quote:

...and consequently, the effective value of the measured voltage at the variable sensor side, as soon as the peak voltage exceeds the diode threshold voltage.

Fine-tuning might be achieved by trying diodes with different breakdown voltages/characteristics (germanium diodes 0.4 volts, Schottky diodes ~0.3 volts, red LEDs 1.3 - 1.6 volts, etc.).

Quote:

That's true... although someone once tried connecting two pairs of diodes in series and reported that the noticeable effect was practically zero. Therefore, experiments with LEDs are probably unnecessary.

Has anyone ever measured the signal with an oscilloscope? I don't have one myself, and I don't know anyone who does. It would be interesting to see.

Quote:

Mine requires 230 volts, but to measure the signal at higher volumes, one would have to drive... unfortunately, I don't have an extension cable that is several kilometers long

.

I can also imagine that interesting effects could be achieved with parallel-connected capacitors or inductors, such as tuning that only works within certain speed ranges.

Quote:

I'm less inclined to believe that, but actually, nothing is entirely ruled out, as long as we don't know why the diodes are functioning in a "speed-selective" manner

.

Hello,

Today, I installed the 10c tuning (on the ESP) in my Passat 35i with the 1Z engine. My potentiometer (linear) is set to 600 ohms (is that perhaps too low, as I'm not seeing any soot), and I didn't notice any increase in power when it was set to 1 kOhm.
I also performed the test by starting the engine while the potentiometer was already engaged. The control unit does not switch to limp mode (no error code is stored), and there is no rough idling, but the idle speed does increase.
Do all those who have installed the 10c tuning experience the problem of the engine idling roughly, or the problem with the limp-home mode?

Regards,
*Mario*

Cheffe wrote:

Today, I installed the 10c-tuning (on the ESP) in my Passat 35i 1Z engine. My potentiometer (linear) is set to 600 ohms (is that perhaps too low, as I don't see any soot), and I didn't notice any increase in power at 1 kOhm. I also performed the test by starting the engine while the potentiometer was already connected. The control unit does not switch to limp mode (no error code is stored), and there is no rough idling, but the idle speed increases. Do all those who have installed the 10c tuning have the problem that the engine vibrates at idle, or the problem with the limp mode?

600 Ohms is usually quite high, if there are no diodes in series with the potentiometer.

The described idle behavior seems "unusual" to me. Usually, the idle becomes unstable first, and aggressive tuning (especially without diodes) often results in a flashing glow plug indicator when starting the engine.
Did you install any diodes?

Hello Ulf,

"No, I only installed the potentiometer and a switch, no diodes. That's why I'm a little surprised that I'm not experiencing this problem with the idle behavior or the emergency mode (thankfully)."
Could I have connected something incorrectly? I mean, I can definitely feel a difference in performance!
What would you consider to be the maximum value that should be set on the potentiometer? Some people who have posted here have set it to below 500 ohms.
"As I mentioned, there was no noticeable change at 1 kOhm; now that it's set to 600 ohms, it's spraying approximately 2 mg/hour into the intake manifold at idle with a warm engine (according to the VAG 1551 diagnostic tool). And when the switch is off, it's spraying about 4 mg/hour."

Regards,
*Mario*

Cheffe wrote:

No, I only installed the potentiometer and a switch, no diodes. That's why I'm a little surprised that I'm not experiencing this problem with the idle behavior or the limp-home mode (thankfully). Could I have connected something incorrectly? I mean, I can definitely feel a difference in performance! What would you consider to be the maximum value that should be set on the potentiometer? Some people who have posted here have set it to below 500 ohms. Okay, as I said, there was nothing noticeable at 1 kOhm; now that it's set to 600 Ohms, it's spraying approximately 2 mg/H into the intake at idle with a warm engine (according to VAG 1551). And when the switch is off, it's approximately 4 mg/H.

At the moment, with this very simple 10c tuning, I can't imagine any fundamental wiring errors that would still result in the desired effect.

I can't answer why you're not experiencing idle problems... the EDC (Engine Control Unit) always seems to have some surprises in store.
Perhaps certain software generations handle the 10c tuning more smoothly than others.

I would consider the onset of noticeable black smoke emissions as the upper limit.
"A more precise" test would be the one performed at 2000-4000 rpm in 3rd gear, where I would aim for a reduction of 15%, with a maximum of 20% compared to the stock condition.

The specification of 2 mg/kWh on the 1551 is obviously nonsense because the standard reference signal (which forms the basis of the evaluation) is severely distorted. That's why even Bor computers with 10c tuning or power boxes show too low fuel consumption values.
In reality, approximately 4 mg are still injected during idle.

It would be interesting to compare this with "20c-diode tuning" and similar performance enhancements, especially in relation to the idle speed reading on the 1551... Could you try that?

If you could explain to me in a little more detail how to install the diodes, I could do that.

*Mario*

I described this on May 16th in this thread. Please look above for .

How about connecting a relay to terminal 61 of the alternator instead of using a switch for the 10c tuning, which would only engage the resistor when the engine is running?

And what is the purpose of this grandiose idea?

...that during self-diagnosis after ignition, the measured values of the quantity control system are either outside of the tolerance range or become implausible, and the EDC (Engine Control Unit) goes into emergency mode even before the engine starts.

See also the corresponding article here.

CU Gremlin.

That only works in the winter. In the summer, I usually start my engine right away, without any delay.

and yet, the volume is increased from 0 to the maximum level.
A self-test doesn't take that long!


CU Gremlin.