30c-Tuningidee für PD-Motoren | Posts 16+

What is the typical diesel temperature increase in a 74/96kW engine (standard configuration) under normal road conditions (highways/motorways) with outside temperatures around 20°C?

Assuming you install a fixed resistor with approximately 200 Ohms, what should the resistor's power rating be?

Hi!

So, even at these temperatures, it never exceeded 75 degrees during my tests, even after longer drives.

A resistance value of 200 Ohms is much (!) too small; the control unit would recognize this as a short circuit and store an error in memory. You must use at least 800 Ohms. I recommend a 1/4 Watt metal-clad version; ceramic also works, but it's not as precise.

Hi!


A resistance value of 200 Ohms is far (!) too small; the control unit would recognize this as a short circuit and store an error in memory. You must use at least 800 Ohms. I recommend a 1/4 Watt metal-clad version, but ceramic also works, but it is not as precise.

Sorry, but that's not correct!!!

I had a 150 Ohm resistor in there.
cheapest accuracy and smallest power

What do you need the accuracy for???
150.0 or 151 or 155 Ohms, to be blunt, doesn't really matter.

and the better temperature drift of metal-based R is also irrelevant.

@ everyone, and this is specifically about diesel temperature sensors, not the LMM (Linear Motor Module).

By "200 Ohms," I mean a slight compromise, as with this size (as I believe), the maximum temperatures of 131° (150 Ohms) are not reached.

I recently ordered some VAG parts from eBay (around 3 euros for both) to protect the resistor and connector.

EDIT
How can I check if my fuel temperature sensor is measuring correctly? My MFA consistently shows a consumption of 0.3 liters too high (on average).

As a replacement part, it costs around 10 euros. How complicated is the replacement? What is the size of the hole in the diesel line for the sensor, and can the leakage of fuel be prevented or limited during removal?

According to my measurements, you will get around 129 degrees with 800 ohms, so you will get somewhere around 160-180 degrees with 150 and 200 ohms, which is much too high.

A resistance value of approximately 780 Ohms should be sufficient to achieve an additional two degrees, however, these are negligible in terms of power increase.

Honestly, I don't understand how you arrived at 150 Ohms! Can someone provide the characteristic value of a sensor from a datasheet?

m3nx wrote:

According to my measurements, you'll get around 129 degrees with 800 ohms, so you'll get somewhere around 160-180 degrees with 150 or 200 ohms, which is much too high. A resistance value of approximately 780 Ohms should be sufficient to achieve an additional two degrees, however, these are negligible in terms of power increase. Honestly, I don't understand how you arrived at 150 Ohms! Can someone provide the measuring range of a sensor from a datasheet?

The measured value of the eBay box is apparently 180 Ohms.

Okay, genau.
that was a measured value
were but 180 Ohms, sorry

Hi!

You are absolutely right, I was actually looking at the wrong sheet the whole time.

That's just how it is when you only measure on small, square pieces of material. I should gradually get into the habit of documenting things properly.

From 150 Ohms, I had an error in the memory, exactly... Now I also know what the 'F' behind the 150 means. I thought it was dirt...



Greetings

m3nx wrote:

Hi there! You are absolutely right, I was actually looking at the wrong sheet the whole time. That's just how it is when you only measure on small, square pieces of material. I should gradually get into the habit of documenting things properly. From 150 Ohms, I had an error in the memory, exactly... Now I also know what the "F" behind the 150 means. I thought it was dirt... Greetings

So, sollten also meine angenommenen 200 Ohm das entsprechende Polster beinhalten, richtig?

Hi,

150 Ohms is too low for most vehicles with LL (Long Life) intervals. This will immediately trigger the "Service" warning. There should be better 180-200 used.

One can clearly see the "scrap factor" of this "tuning method" from the different reactions of the vehicles.

How can I determine if my fuel temperature sensor is functioning correctly? Are there any reference values for comparison?

bloeckler wrote:

How can I determine if my fuel temperature sensor is functioning correctly? Are there benchmark values for comparison?

Hi,

Best measure when the engine is cold.
approx. Target values:
10°C -> 10 kOhm
20° -> 6,2 kOhm
30° -> 4.0 kOhm.

ulf wrote:

How can I determine if my fuel temperature sensor is functioning correctly? bloeckler wrote: Are there benchmark values for comparison? Hi, Best measure when the engine is cold. approx. Target values: 10°C -> 10 kOhm 20° -> 6,2 kOhm 30° -> 4.0 kOhm.

Great, thanks.

I had temporarily connected a 1kOhm potentiometer and set the value to @250. There was noticeably more pulling power and maneuverability.

bloeckler wrote:

I had temporarily connected a 1kOhm potentiometer and set the value to 250. There was noticeably more pulling power and playfulness.

Beautiful... but the real truth is that, no matter what (fixed) resistance you take,
The colder the engine, and therefore the more sensitive it is, the higher the performance gain.

I am currently collecting data on this tuning method and will soon be adding the 10c-article.

ulf wrote:

I had temporarily connected a 1kOhm potentiometer and set the value to bloeckler wrote: 250. There was noticeably more pulling power and playfulness. Beautiful... but the real truth is that, no matter what (fixed) resistance you take, The colder the engine, and therefore the more sensitive it is, the higher the performance gain.

Okay, I'm ready. Please provide the text you want me to translate. I will maintain all s exactly as they are and only provide the translation.

For example, is a Powerbox intelligent enough to always compensate for the difference in resistance depending on the fuel temperature, so that the increase remains constant?

bloeckler wrote:

For example, is a power box intelligent enough to always compensate for the resistance difference, depending on the fuel temperature, so that the increase remains constant?

Hi,

One can also get it for a lower price than a (typical) Powerbox:
The Water-Giving NTC 06A 919 501 constantly deceives the engine computer with a ~20°C too high diesel temperature, and, as far as I know, costs less than 20€.
It can be easily replaced, as it actually has the same housing dimensions as the diesel injector insert

I will investigate the effects soon with the DZR. . .