VP37 ESP: Cleaned Powder Meter According to Instructions.

"My Audi 80 (04/94, 90 HP, engine code: 1Z, 360,000 km) was experiencing jerking in the higher gears."
when gently accelerating.
If I pressed the accelerator fully, the jerking stopped. The idle speed was also fluctuating.
Following a tip from the forum, I disconnected the cable from the speed sensor.
Removed from the transmission - the jerking stopped.
Based on the symptom and the absence of any other cause, my diagnosis was...
a difficult-to-operate quantity control valve .

The day before yesterday, there was a lot of stress, and now it's also shaking in 2nd gear , and I was able to...
Avoid constantly switching between full acceleration and coasting in city traffic.
It's great that I can use the instructions here to clean the quantity setting mechanism.
I finally dared to try something I saw in a forum. To calm my nerves (the warnings in the instructions are...).
Yes, definitely, there was a spare ESP unit in the trunk.

The turnout mechanism - especially the magnetic parts - was full of metal debris .
Otherwise, the internal components were in good condition. There was no detectable radial play in the shaft.
The rotary magnets are smooth, and everything moves easily. What surprised me was the fact that...
that the wave's mobility has not changed .
IMHO, the metal abrasion between the electromagnet and the torque magnet causes...
that the magnetic field is altered in its effect and, as a result, the precision of the...
Momentum is lost.
I previously had the impression that the metal wear was caused mechanically by the movement.
would have a significant influence .

After cleaning and painstaking reassembly onto the ESP (Electrical Submersible Pump) - drilling the ring.
It took me five attempts to finally get the timing right by adjusting the quantity control valve.
It's almost like flying blind and can be nerve-wracking - is the shaking completely gone ?
Even the idle speed is now stable, and as a special addition, the maximum speed has increased .
By repositioning the MSW on the ESW, the injection volume has changed from 4.8 to 5.0.
changed to 5.0-5.2. IMHO, I think I can probably leave it like this .

My thanks again to the three authors.

MichaelJ

MichaelJ wrote:

The turnout mechanism - especially the magnetic parts - was full of metal debris .

Do you have any idea (or have you seen anything) that might indicate where the wear is coming from?
What was the nature of the abrasion? Was it in the form of chips (what length, what thickness), or small fragments (size?), or dust...?
Magnetic material? (Actually, that's a silly question if it mainly depends on the magnetic parts, but still - you never know).

Quote:

What surprised me was the fact that the wave's mobility did not change . IMHO, the metal abrasion between the electromagnet and the torque magnet causes... that the magnetic field is altered in its effect and, as a result, the precision of the... Momentum is lost. I previously had the impression that the metal wear was caused mechanically by the movement. would have a significant influence .

That's exactly what I thought: The friction and difficulty in rotating the MSW shaft are likely caused by "dirt" in the bearings.
However, if the wave exhibits the same ease of movement before and after the event, then, in my opinion, the only remaining explanation is a change in the magnetic properties.

Quote:

Is the stutter completely gone:D? Even the idle speed is now stable, and as a special addition, the maximum speed has increased .

A great success .
At Bosch or VAG, they probably would have sold you a new ESP (Electronic Stability Program).

Quote:

By repositioning the MSW on the ESW, the injection amount has changed from 4.8 to 5.0. changed to 5.0-5.2. IMHO, I think I can probably leave it like this.

Sure, no problem.

"@Ulf - so, those weren't really shavings. Most of it was more like a kind of flour, similar to graphite powder. Some parts had clumped together into small crumbs, about 1-2 mm in size/length - in my opinion, due to magnetization. Due to the magnetic properties, it's likely steel. The most difficult part was getting the shavings away from the magnet near the entrance opening. They would fly back towards the magnet from the Q-tip when I pulled the Q-tip away. In my opinion, this ring magnet embedded in the bottom of the housing serves to keep the MSW clean. Since everything in the MSW is contactless, there can't be any wear and tear there. It probably comes from the ESP itself, where the bearings and shafts rub.
I experienced a slight jerking sensation 5,000 km ago when I took possession of the car, and I thought I could solve the problem by adding diesel cleaner. The only thing that was resolved was the metal debris in the ESP, which then migrated to the MSW and intensified the jerking .
The ring magnet was so covered with debris that I didn't realize it was sitting in a recess until I scraped away at it several times. This coating likely prevented it from attracting other parts, which then moved towards the rotating and electromagnets.

Regarding Bosch and VW - yes, they wanted to sell a completely new ESP . There isn't even a screw to replace the one with the triangle. I then obtained two from a screw supply store.

What I'm still considering is the question of whether the MSW (Mass Air Flow sensor) really needs to be disassembled from the ESP (Electronic Stability Program) . There are no screws on the underside that need to be accessed. The underside is only interesting for cleaning the ring magnet. If I find a solution for cleaning the ring magnet, cleaning the MSW would be a "piece of cake" because then the risky process of inserting the cam of the throttle valve into the ring and positioning the MSW on the ESP would be eliminated. What I don't know is whether the cam rotates the ring enough when the sensor is removed from the shaft that it would slip out of the hole .

Hello Michael!

I am very happy to hear that you have managed to completely eliminate the jerking from your pump .
I've also read the technical article about cleaning the MSW several times, as my pump also tends to stutter slightly. However, so far, the problem hasn't been severe enough for me to actually go through with such a procedure.
Here are the points that I am still interested in:

Have you replaced the (O-rings?) between the metering skimmer and the pump, as well as between the metering skimmer cover and the metering skimmer housing? If not, have you experienced any problems with leaks?

2. In the figures of the technical article, one can see the connection bore between the MSW housing and the pump chamber. Based on my experience, the metal abrasion does not originate from the components inside the MSW, but from the hydraulic part of the ESP. Therefore, I believe that an improvement could be made by designing and installing a fine filter for the connection bore. This should solve the problem permanently . This could also be an approach for a preventative measure to protect pumps from jerky operation before they fail.

Were there any other issues that are worth mentioning?

Thank you for your feedback on the technical article. It has encouraged me even more to carry out the MSW cleaning in the near future!

Regards,
Alex.

In my opinion, an improvement could be made by designing and installing a fine filter for the connection hole. This should solve the problem permanently .

And if the filter gets clogged, you'll get a massive backflow!

The impeller pump delivers approximately 4 cc per revolution, which builds up the internal pressure. This pressure should ideally only be influenced by the overflow valve located at the top of the MSW unit (and can reach up to 12 bar). I would advise against adding another (non-serviceable) filter in between...

CU Gremlin.

Oops, I didn't realize, from memory, that the drain is integrated into the MSW housing.
Then I'm not surprised that all the wear and tear remains stuck in the MSW .
It would have been possible to implement the process at the pump housing (hydraulic component) to prevent all that sludge from eventually ending up in the municipal sewage system.

Then, the fine filter located between the municipal solid waste (MSW) and the pump housing represents an unpredictable risk, and the pressure loss it causes could potentially disrupt the internal pressure regulation system.

Regards,
Alex.

@ donalexo - Round cord seals oh - I forgot .
but the instructions stated that they would cooperate. I also couldn't find them in the parts list, and since I couldn't get a screw for the MSW (the one with the triangle) from either Bosch or VAG, I assumed that this seal couldn't be purchased through normal channels . Therefore - the ESP is tighter than before .
Before cleaning, a small amount of diesel was leaking between the MSW (Multi-Stage Washer) and the ESP (Electrostatic Precipitator). After tightening the screws on the MSW in a criss-cross pattern with a torque wrench after the final adjustment, the seam on the sides is now dry.

The only problem, in my opinion, is inserting the cam into the ring. You absolutely can't see in the last centimeter whether everything is aligned correctly, or whether the cam is misaligned, which could cause it to break during the first start, or the engine could exceed its maximum RPM.