SEO: Best German to English Translation Services | Posts 16+

Because I now have a set of large elements for my AJM .

The question is, what happens if I just install them?

DaBibo wrote:

Because I now have a set of large elements for my AJM . The question is only what happens if I simply install them...

Hi,

My answer is "try it out" - and post your experiences as a test pilot here .

But before you get started, carefully examine the design of the adjustment screw and its corresponding part (ball joint?) in the injector to see if the new injectors are compatible with the screw -> do they have the same shape as the old injectors?
There are, AFAIK, different designs... if they don't fit together properly, at the end, two balls or two plates might press against each other -> which, after being started, would quickly result in a lot of metal scrap .

It will take a little while before I have time for that .

If they inject significantly more fuel, I might just build myself a fog machine.

How is the precise fuel injection amount monitored in a PD (presumably referring to a specific engine or system) system?

DaBibo wrote:

How is the exact injection amount actually monitored in PD?

Hi,

AFAIK, the injection quantity is determined by the opening time of the injector (which is controlled by the engine's computer) in conjunction with the corresponding "pump" characteristic curve (which relates engine speed to opening time and thus determines the injection quantity).
Based on the voltage curve at each PD solenoid valve, the engine control unit can determine the actual opening time.

When replacing the injectors with non-original parts, the "pumping" characteristic curve no longer matches, meaning the engine computer doesn't detect the fake – unless the differing electromagnetic properties of the injectors reveal the tampering... -> Error entry .

ulf wrote:

...When replacing the injectors with parts from a different source, the "pumping" characteristic curve no longer matches...

Hi Ulf,

With the "pump characteristic curve" built into the injectors, there's not much else to adjust. The fuel quantity is determined solely by the pump plunger and the attached nozzle (cross-section). The stroke and (mechanical) timing are determined by the engine control unit (ECU), which is the same for all diesel engines. Everything else is controlled by the ECU.
It's possible that a PD (power distribution) element from a 130 series, which is being operated by the STG (steering tilt/telescope) module from a 100 series, remains open for far too long. Anyone can imagine the consequences (though it doesn't necessarily have to happen).

Bertil wrote:

With the "pump" characteristic curve in the injectors, there isn't much left to adjust. The amounts are only determined by the pump plunger and the attached nozzle (cross-section). The stroke and the (mechanical) timing are determined by the engine control unit (ECU), which is the same for all PD engines. Everything else is determined by the control unit.

Hi Bertil,

Similar to the VP 37 (where the injection angle must increase with increasing engine speed to maintain the injection quantity):
If the injector, for example, is controlled with an injection angle of 10° KW, once at 1500 rpm and once at 4000 rpm, will the same amount of diesel enter the cylinder in both cases ?

If a diesel engine in a PD (pre-combustion chamber) system already gets very hot due to compression effects, then, in my opinion, for the same injection angle (duration), the injection amount should decrease as the engine speed increases!

ulf wrote:

similar to the VP 37 (where the injection angle must increase with increasing engine speed to maintain the injection quantity): If the injector, for example, is controlled with an injection angle of 10° KW, once at 1500 rpm and once at 4000 rpm, will the same amount of diesel enter the cylinder in both cases ? If, in a PD (Pumpe-Düse) diesel engine, the diesel fuel is already strongly heated due to compression effects, then, in my opinion, with the same injection angle (duration), the injection quantity should decrease with increasing engine speed!

Hi Ulf,

We passed each other.

Of course, the amount (via the injection angle) and the timing are electronically controlled in the PD system.
What I meant is the following;
If you only change the nozzles on the VP37 pump, it's possible that the pump may provide slightly less pressure for atomization due to the larger nozzle orifice, which can negatively affect the spray pattern. The pump and nozzle should always be considered as a unit for achieving the correct spray pattern.
With PD systems, you don't have this problem because you replace the entire pump assembly, including the nozzle, at the same time.
You definitely won't have any issues with the spray pattern when using PD Tuning.

We had thought about it a long time ago that a single-cylinder pump with the "huge" injectors from a VW bus might not produce a proper spray pattern, because the pump might not be able to deliver enough diesel, and the injector might therefore "drip" (instead of properly atomizing). The PD injector doesn't have this problem.
If you are now incorporating larger PD elements, the spray pattern is guaranteed to be correct. Therefore, it is not necessary (as it often is with VP systems) to adjust the pump to the nozzles.

That's what I meant by "pump characteristic curve."
I hope I have expressed myself more clearly now.

In the PD system, only the injection timing and the angle, calculated by the STG based on peripheral parameters, are reported to the PD element. The amount is then automatically determined from this information.

Theoretically, it's even possible that a PD150 (due to the larger nozzles) could inject fuel for a shorter duration than a PD100. This could lead to unexpected effects if a PD150 element is used with a PD100 control unit (more fuel like in the 150, resulting in a misting effect). In such cases, the amount of fuel might need to be adjusted using a modified control unit.



P.S. The PD system is mechanically far more primitive than a VP system... unfortunately, it requires a much more complex electronic system.

Bertil wrote:

The PD system is mechanically far more primitive than a VP system... unfortunately, it requires electronics that are vastly more complex...

Hi Bertil,

However, the design of the common rail system also has its complexities. How is it prevented, especially with high mileage and corresponding frictional wear, that diesel fuel leaks between the pump body and the pump plunger upwards towards the rocker arm/valve cover area, and thus gradually dilutes the engine oil?

Hi Ulf,

You should take a look at older series pumps (e.g., old DC motors). The PD pump is, in principle, a single-stage series pump.

The individual pumps are, incidentally, available as standard catalog items with an injection volume of 18,000 mm³ (eighteen thousand!) per stroke...and more .

CU Gremlin.

Bertil wrote:

You should take a look at the older series pumps (e.g., old DC motors).

The PD pump is, in principle, a single-stage series pump.
Hi Bertil,

Unfortunately, I do not have access to any positive displacement pump hardware or related information materials.

Please tell me about 3 keywords as an answer (or a link), and I would be satisfied with that .

ulf wrote:

You should take a look at the older series pumps (e.g., old DC motors). Bertil wrote: The PD pump is, in principle, a single-stage series pump. Hi Bertil, Unfortunately, I do not have access to any positive displacement pump hardware or related information materials. Please tell me about ~3 keywords as an answer (or a link), and I would be satisfied with that

.

Let me see if I have anything (in writing) about it. An old diesel mechanic (now retired) explained how it works to me once when I was at a Bosch service center... unfortunately, I didn't really understand it.

I have one set of new injector elements from a 150 HP engine. If anyone is interested, they can contact me.

Regards,
BM

I have the same thing, and I'll soon be getting the larger turbocharger too.

Let's see when I'll have time to install it. First, I have to go to the TÜV (technical inspection) in February...