Tightening torque of the union nut for nozzle tips (VEP ESD)

Hi,
The nozzle tip on the ESD (Electrostatic Discharge) device, along with the NHG (likely referring to a specific material or component), should be placed in the ultrasonic cleaning bath.
Background: The LLR (Low-Level Regulator) is showing fluctuating readings of 1.5 - 2 mg/stroke too high for this ESD (Electronic Spray Deflector). The limit according to the manufacturer's specifications is 1.5 mg/stroke. The compression is approximately the same (+/- 1 bar) on all cylinders, so it's not a compression issue. It's not the pressure equalization valves either, as the problem persists even with a new ESP (Exhaust Gas Recirculation) unit. The injection pressure is around 190 bar (similar to a second ESD on the engine for comparison). The spray pattern is noticeable with the higher injection quantity; in some cases, it doesn't atomize properly.
I will disassemble it according to the instructions in /viewtopic.php?t=10197. However, I am still missing the torque specification for the nozzle tip retaining nut. Can anyone help me with that?
Sure, here's the translation:

"Best regards."
Herbert.

Hello Herbert,

I can't provide precise values, but you'll feel a point where it can't be tightened any further.
If you don't want to upset your mother, then you should just leave it as it is.

It's quite tight, a ring wrench or socket wrench is necessary; a combination wrench won't provide enough torque. The best way to determine the correct size is to use the loosening point when screwing it on as a reference.

Best regards, Rainer.
PS: I might have some spare nozzles lying around; please let me know the number printed on the nozzle.

Hello Rainer,
The phone number is 028 130 201 H or HX. Bosch refers to it as 0 432 193 837.
I found a torque specification of 33 ft lb, which is approximately 45 Nm, on a North American website, referencing a Bosch workshop.
hg
Herbert.

I meant the number on the nozzle, not on the nozzle holder .

Here's another tip: After 1-2 rotations, give the nozzle tip a firm tap (with wood, if you want to reuse it), otherwise, carbon buildup can cause the nozzle tip to rotate and the guide pins can break off.

Hello Rainer,
First of all, thank you for the feedback. I will disassemble it with great care and attention.
The ESD is still installed, but the vehicle will definitely still run until the weekend.
From DieselSend, I have the following part numbers for the injector holder combination 0 432 193 837:
Bosch DSLA150P357 (0 433 175 058), repair kit 2 437 010 083.
hg
Herbert.

Quote:

DSLA150P357

Too bad, none left.

Best regards, Rainer.

Nevertheless, for verification.
The nozzle should be resistant to alcohol (I wanted to use it in an ultrasonic cleaner), right?
hg
Herbert.

Herbert wrote:

The nozzle should be resistant to alcohol (I wanted to use it in an ultrasonic cleaning bath)?

Yes, but don't get your hopes up too much...

Hi,
The ESD (Electrostatic Discharge) protection is installed and dismantled.
Before loosening the lock nut, it's best to carefully verschandeln the area between the nut and the nozzle tip with the brass brush.
After loosening, the mother gently rotates the coal back and forth, which dissolves the coal in that area.
The nozzle tip was thoroughly cleaned in the ultrasonic bath, and all carbon deposits are gone. However, multiple cleaning cycles are required. Cleaning with alcohol (spirit) is worse than cleaning with water.
Final cleaning should be done with alcohol to remove any remaining water. I cleaned the other parts in the ultrasonic cleaner using only alcohol.
The structure of the ESD is well illustrated in /viewtopic.php?t=7444. However, the guide bushing 8 surrounds the upper spring 6, and there is a washer between the lower spring 6 and the pin 2.
Under the magnifying glass, all parts can be seen to be verschandeln after the ultrasonic cleaning. It's best to leave them as they are, as each cloth leaves behind lint.
(Modified) The pattern of the five holes on the cone of the nozzle tip is asymmetrical. One hole is near the tip of the cone, the two adjacent holes on the left and right are deeper, and the last two are near the base of the cone. I suspect that this is related to the angled mounting position of the ESD in the ZK. In other words, the nozzle tip is aligned such that the injection holes are equidistant from the center axis? The alignment is determined by the pins of the intermediate disc.
hg
Herbert.

Quote:

In other words, the nozzle tip is oriented such that the injection holes are equidistant from the center line?

Correct, the nozzle is also angled in the Z-axis.

Hi,
The ESD has been reassembled and installed back into the engine.
I had marked the position of the retaining nut relative to the nozzle holder before disassembling it. When the tightening torque reaches 40-45 Nm, the markings will align again.
For those who are planning to do it, here's a summary:
- Carefully verschandeln the nozzle throat in the area of the female thread with the brass brush before loosening (the nozzle here was only slightly clogged with carbon deposits, except for some areas that were severely blocked).
- Secure the nozzle in the vise using appropriate aluminum profiles on the sides;
- To loosen the nut, use a long socket wrench with a 15mm socket, such as a Proxxon. A stillson wrench is useless for loosening it; you'll only damage the nut itself. A ring wrench will also quickly slip and damage the sides.
- After the initial loosening, gently move the mother plant back and forth before continuing to carefully separate it;
- The nozzle, spacer disc, and nozzle holder will inevitably be contaminated with leaked coolant (DK) and soot when the nut is loosened. Cleaning is best done using an ultrasonic cleaner, and this is essential.
- Water cleans better in an ultrasonic bath than alcohol, but because of the potential for water residue, I only used it on the nozzle itself, and then cleaned it again with alcohol at the end.
- Before assembly, apply a small amount of diesel fuel to all parts.
Unfortunately, the success was quite limited. The LLR values improved only slightly, but the nozzle is clogged when it's warm, so I probably have to replace it.
hg
Herbert.

Hi,
After one week / approximately 300 km of operation, the LLR (likely referring to "lifetime learning rate" or a similar metric) has improved significantly.
Cylinder #3 is still slightly weaker, but the deviations are now only 0.8 - 1.0 mg per cycle, and even as low as 0.3 mg per cycle after starting the engine (all measurements taken with a warm engine).
The tolerance limit would be 1.5 mg per dose.
The nozzle is no longer secured with nails.
Immediately after reinstallation, I observed a deviation of between 1.6 and 1.9 mg per actuation.
The ESD (electrostatic discharge) was slightly lower (approximately 1 mg/port) from the moment of installation, with very consistent compression values.
I'm satisfied with it for now.

hg
Herbert.