Diesel pump 1Z: Differences and comparison

Hello,
What is the difference between the following fuel injection pumps?
VW 028 130 109H or Bosch 0460 404 994.
VW 028 130 110H or Bosch 0460 494 985 (may also be 0460 404 985).

Visually, the parts look identical, and the connectors also fit. Could the parts be exchanged without causing any damage?
Thank you and best regards,
Harri.

Hi,

I also wanted to replace my fuel pump and had researched two different models, one of which was from the AFN engine.
Okay, so the 1Z and the AFN pumps both had almost the same flow rate, which shouldn't be the case (according to the Bosch service), but the impeller vanes of the AFN pump are steeper, which means the AFN pump provides a higher inlet pressure.

Both pumps are actually designed for the 1Z engine. The 028 130 110H is supposed to be from a 1996 Golf TDI, and the 028 130 109H is from a 1995 Passat TDI. Both are 1Z engines.
Best regards, Harri.

@turgumu:

Quote:

So, the 1Z and the one from the AFN both had almost the same flow rate, which should be different (according to the Bosch service), but the impeller vanes of the AFN pump are steeper, so the AFN pump provides a higher inlet pressure.

This statement is simply wrong!

The pump only controls the delivery volume via the flow control element (adjustment of the metering sleeve). The pressure that builds up between the pump and the injector nozzle is primarily determined by the nozzle opening cross-section and the pump speed.

For the 038 engines (AGR, AHF, ALH, ASV), the same fuel pump is installed (including the identical plunger). The only differences are in the fuel injectors (specifically, the injector holder combinations) and the EDC control unit maps.

Unfortunately, I'm not very familiar with the 028 engines. Perhaps the difference lies in the internal sensor technology of the pumps. The older 1Z pumps supposedly still used potentiometer sensors, while the newer ones use contactless HDK sensors. Maybe that's the difference. What year is your 1Z from?

Regards,
Alex.

Okay, my Passat is from 01/95 and has the contactless sensor. You can tell whether the pump has a potentiometer or not by looking at how the diesel return line is connected: if it's horizontal (contactless) or if it goes straight down from the top into the pump (through the hollow screws). In both cases, they are horizontal on the top cover of the pump. There must be some other difference, though.
Best regards, Harri.