VCDS and OBD diagnostic device in the On-Board Diagnostics Shop
Diesel, Engine Technology and Vehicle Technology. Repair, Maintenance and Diagnostics (OBD).

Bosch HFM 5: Specs & Pierburg Equivalent

 
New Topic Reply 🔗 🖨 Dieselschrauber - Index » Diesel Engine Technology
Author Message
joergs
Guest




 


Free account, no CAN development support

Post23-12-2003, 14:52    Subject: Bosch HFM 5: Specs & Pierburg Equivalent Quote

Hello fellow DIY enthusiasts!

I'm urgently looking for datasheets, specifically for the Bosch HFM5. I'm particularly interested in the diagram showing the relationship between air mass per unit of time and output voltage. I've already searched Google and here, but haven't found anything useful. Does anyone have a link they can share quickly?


Translated on 08-08-2026, 10:17.
Back to top
diesel.gustav
Guest




 


Free account, no CAN development support

Post25-12-2003, 20:15    Subject: HFM5 Specs: Characteristics and Data Quote

Deleted upon request.


Translated on 08-08-2026, 10:18.
Back to top
joergs
Guest




 


Free account, no CAN development support

Post25-12-2003, 20:28    Subject: Bosch HFM 5: Specs & Pierburg Equivalent Quote

hello diesel_gustav,


I possess this Bosch datasheet. The specifications are not bad. However, it's unfortunately not easy to find the sensor that might be used in the 1.9 TDI engines. I can't find the Bosch number that is on my mass airflow sensor (MAF) anywhere in the document. I did some calculations and decided on the third option. I hope it fits. Yesterday, I also roughly determined the functional equation (wow, that was a struggle. It shows how long it's been since I last used curve discussions, integration, and differential calculus!). Well, tomorrow, I think it might be time for my fake prototype MAF sensor to live out its bitter existence on an Atmel AVR microcontroller. icon_razz.gif

thank you anyway!


Translated on 08-08-2026, 10:19.
Back to top
diesel.gustav
Guest




 


Free account, no CAN development support

Post25-12-2003, 21:54    Subject: HFM5: The Ultimate Guide Quote

Deleted upon request.


Translated on 08-08-2026, 10:20.
Back to top
joergs
Guest




 


Free account, no CAN development support

Post25-12-2003, 22:09    Subject: Bosch HFM 5: Specs & Pierburg Equivalent Quote

Oops.


1900ccm is equivalent to 475ccm per stroke.
475ccm * 1.29g/l = 612 mg/dose
612 mg/vial * 0.8 (delivery rate) ≈ 500 mg/vial

'With each rotation, there are 2 suction strokes. The idle speed is approximately 800 RPM, and the system pressure is 1 bar. This results in 400 suction strokes per minute, which translates to 2 * 500 mg * 400 * 60 = 24 kg/h. These 24 kg/h should correspond to approximately 2 V (see ULF's explanations regarding the LMM).'

And all of that at full capacity.

475 * 1.29 * 0.08 ≈ 500mg/dose * 2.3 bar charging pressure ≈ 1150mg/dose
1150mg per tablet, two tablets per dose, 4000 revolutions per minute, output of approximately 550 kg/hour. This 550 kg/hour should correspond to roughly 5 units.

Do I have a misunderstanding here?


Translated on 08-08-2026, 10:22.
Back to top
New Topic Reply 🔗 🖨 Dieselschrauber - Index » Diesel Engine Technology
Similar articles and topics
Topic Forum
No new posts How to analyze data from a temperature sensor? Diesel Engine Technology
No new posts VW-Blaue Beleuchtung, technische Daten Diesel Engine Technology
No new posts WIV data for the Polo 9N 2004 On-Board Diagnostics (OBD)
No new posts Peugeot HDi: Technical issue, but expensive!! On-Board Diagnostics (OBD)
Jump to:  
You cannot post new topics in this forum.