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Good morning,

I have to buy a fuel sensor sender using on my g3x.

Looking to instal on position 2  before fine filter.

Needs differenzial fuel pressure also on this position or differenzial pressure sensor is required only on position p1 near fuel injector?

 

How do you connect the line on diff. Pressure sensor to airbox?

 

Grazie

 

MArco

  • Re: Differenzial fuel pressure sensor on position p2

    by » 6 weeks ago


    The differential fuel Pressure sensor is installed in the hose After the fuel pumps and Before the fine filter.
    The airbox pressure can be sampled by inserting a Tee connector in the small hose between the Airbox and the Fuel pressure regulator near the #4 cylinder.


    Bill Hertzel
    Rotax 912is
    North Ridgeville, OH, USA
    Bill.Hertzel@Yahoo.com
    Clicking the "Thank You" is Always Appreciated.


  • Re: Differenzial fuel pressure sensor on position p2

    by » 6 weeks ago


    My 912is is one of the early ones, (sn 4417255). When the sport modification came out I received the kit, including a new airbox, It has a screw near the hose nipple used for airbox pressure to the fuel regulator. This item is shown in illustrated parts catalog 912iSC/912iS, edition 1, rev 0,of March 10/2012 page 2 as item 8. Subsequent revision of the manual do not show this screw. So it begs the question, Is this a port which can be used as a source for differential pressure testing or is its purpose to hold some internal part of the airbox? From this I assume the newer airboxes do not have this screw.


    Thank you said by: Bill Hertzel

  • Re: Differenzial fuel pressure sensor on position p2

    by » 6 weeks ago


    The Screw is still shown in the Ed.4, Rev.0 (Feb 2019) Parts Catalog.
    It serves no purpose other than to close the hole.
    It is the same thread as the Hose Nipple (#10) directly next to it that connects to the fuel pressure regulator.
    I will guess that it exists so that a second hose nipple could be installed to allow a MAP Gauge and/or Differential Fuel sender to sense the manifold pressure.

    I wish I was aware of this screw before I had drilled and tapped my own barbed fitting for my Fuel sender.

    Good Call!


    Bill Hertzel
    Rotax 912is
    North Ridgeville, OH, USA
    Bill.Hertzel@Yahoo.com
    Clicking the "Thank You" is Always Appreciated.


  • Re: Differenzial fuel pressure sensor on position p2

    by » 6 weeks ago


    Many thanks for reply.

    My avionic supplier told me to use absulute pressure sensor and not differencial.

    I m not really sure if his reply.

    On heavy installation manual, sys description page 235  73 00 00 page 4 call for absolute pressure sensor to misure furl press.

    Still have my dubd

     

    MArco


  • Re: Differenzial fuel pressure sensor on position p2

    by » 6 weeks ago


    Marco Stated:

    " On heavy installation manual, sys description page 235  73 00 00 page 4 call for an absolute pressure sensor to [measure fuel] press. "

    That is an obvious error in the manual.  (They do have errors!)   
    The Pressure is regulated by the engine to be at a 3 Bar Differential above the MAP pressure.
    It follows that if you want to measure the fuel pressure, you will need to measure the same differential pressure, or else it will appear to be varying all over the place.

    An Absolute Sender is used in the Normally Asperated Engines.
    A Differential Sender is needed for the Fuel Injected and Turbo Charged Engines, both of which regulate their fuel pressures at a set differential from the Manifold pressure which varies with the throttle.

    Attention ADMIN !!!


    Bill Hertzel
    Rotax 912is
    North Ridgeville, OH, USA
    Bill.Hertzel@Yahoo.com
    Clicking the "Thank You" is Always Appreciated.


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