Pump Nozzle Tuning: Cheap DIY Guide & Tips

Hello,
I used to have a 1.9 TDI and it had a custom-built tuning box installed.
I would like to implement this recipe in my 115 HP PD (presumably referring to a specific device or system).
Has anyone already planned a tuning project like this?
You can actually buy it at the world-renowned auction house, but it costs around €50 when it's being discontinued, even though the individual items only cost a maximum of €5.
Who has a wiring diagram, or how far along is anyone with that?
Please help me.
I THINK THIS WILL ALSO INTEREST MANY PEOPLE HERE.

I'm also interested in that. I have a Polo TDI with a 100 hp common rail engine.
So, does anyone have a clue here?

Am I correct in assuming that, in a pre-combustion chamber (PD), there is essentially only a resistor between the two cables , but that here, the power increase is achieved by raising the temperature of the diesel fuel using a resistor }?
Here, the engine control unit (ECU) is being tricked into thinking that the diesel is hotter and injecting more fuel (or something similar).

Maybe someone has a detailed plan for that.

Hi suggermilk,

Unfortunately, it's not quite that simple with PD.
You'll achieve a power increase of around 1-2% by adjusting the diesel temperature (if at all). We discussed this before on this forum regarding VP Diesels.
All PD tuning boxes that I have seen so far manipulate the signal to the PD elements in real-time. This means that a processor-controlled circuit is required.
Unfortunately, there aren't many parameters that can be used for tuning purposes in PD (presumably referring to a specific software or system).

@bertil
It can't be that difficult, since it's already being sold on eBay.
If nobody knows anything, then there's nothing I can do.
According to eBay listings, this item should be worth between 10 and 12 pounds, and it only connects with two cables.

suggermilk wrote:

@ bertil It can't be that difficult, as it's already being sold on eBay. If nobody knows anything, then there's nothing I can do. According to eBay listings, this item should fetch between 10 and 12 pounds, and it only connects with two cables

.

Give it a try!! I think these things are junk!!

I can only tell you what I know and what seems logical to me.

Also, take a look here: /viewtopic.php?t=299&highlight=tuning+kraftstofftemp%2A

Hi suggermilk,


Here are some more thoughts on the 10-cent tuning adjustment using the fuel temperature sensor.

The fuel system of the PD (Pump Deno) engine is slightly more complex than that of the VP (Valve Port) engine. In the PD engine, fuel temperature is not only used to determine the injection timing but also to regulate the thermal balance of the fuel system.
Vorweg ist zu bedenken das der Kraftstoff den (warmen) Zylinderkopf durchqueren muß um die PD Elemente zu erreichen. Es ist daher nötig durch gezielte Maßnahmen den Kraftstoff zu kühlen und an allen Elementen die gleiche Temperatur zu gewährleisten. Dazu gibt es die Möglichkeit den warmen Kraftstoff mit kaltem zu mischen. Dafür wird der kältere Rücklauf teilweise kurzgeschlossen. Ein extra Kühlmittelkreislauf mit Temperatur geregelter Pumpe ist vorhanden, der den Kraftstoff bei immer noch zu hohen Temperaturen weiter runterkühlt. Der durch den Rücklauf zurückfließende Kraftstoff darf auch nicht zu warm werden dafür sind diese Kühlmaßnahmen vorhanden. Diese Cooling mechanisms are regulated by the fuel temperature sensor.
Wenn du jetzt dem System einen niedrigere Temperatur vorgaukelst, dann werden die Kühlkreisläufe nicht (bzw. zu spät) aktiviert, die effektive Temperatur läuft hoch und es kann passieren das extrem warmer Kraftstoff in den Tank zurückläuft. Im Extremfall kann dabei der Tank beschädigt werden (der ist aus Kunststoff). Ich habe das vor einem Jahr schon mal gesehen und habe mich damals gewundert das der Meister sagte: "...das kommt von den billigen Tuningboxen...". At the time, I thought he was a bit crazy, but now that I'm learning more about PD technology, I understand the problem.
By the way, the temperature sensor in the PD (pump distributor) is located in the fuel return line of the fuel system! Why do you think that is?

Hello Bertil,

Only some PD TDI engines have an active fuel cooling circuit (especially the earlier models). For example, the AJM engine only has an air-cooled component in the fuel circuit, which is always active.

Michael II wrote:

... Only some PD TDI engines have an active fuel cooling circuit (especially the earlier ones). For example, the AJM engine only has an air-cooled component in the fuel circuit. This is always switched on.

That's mostly correct, but I generally find manipulating the temperature values in the pump injector system too risky. By the way, I saw a new 150 PD TDI (engine code ???) with an active fuel return system. It seems that the "smaller" PD TDIs don't have it.
The documentation for the AXR engine (74kW EU4) that I have also mentions an actively controlled fuel cooling system, but I can't figure out from the description.

Hello,

This very fact (active/passive cooling, sometimes installed and sometimes not) shows that you shouldn't tamper with the fuel temperature sensor. The system is probably too critical for that.

Hello,

PD tuning is also somewhat more difficult for another reason:

The control unit not only activates the valves of the proportional pressure elements via the control lines, but also measures the current flow to determine the precise opening time of the valve (the closing current is higher than the holding current). This must also be taken into account when tuning proportional pressure systems using an external module.