Fuel Flow sensor Install

Re: Fuel Flow sensor Install

by Robert Hannigan » 6 years ago

Robert Hannigan

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I will get back to you tomorrow with more information.

Re: Fuel Flow sensor Install

by Robert Hannigan » 6 years ago

Robert Hannigan

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Ok thanks Bill I will fly tomorrow and record all the setting I get on the sensor and the dip stick readings.
I will try unplugging the sensors tomorrow and let you know. AND hey thanks for all the help.

Re: Fuel Flow sensor Install

by Robert Hannigan » 6 years ago

Robert Hannigan

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Bill I flew today and recorded some data : at 2000 flow 6.9, 2500-7.5 4000-9.7 5200- 11.0 I tried to fly for one hour but screwed up and did not get the time off and on estimate 1hour 12min.

I set the sensor fuel at 22 gallons when I returned the instrument said I used 13.6 gallons and had 8.4 left.
I had the low fuel alarms set at 6 gallons and the alarm kept coming on at the end of the flight.

When I dipped the tanks at the start the RIGHT tank 4.3/4 inch end 3.7/8 LEFT start 4.0 end 3.1/2 I have not added fuel yet to check how much I used. Its getting hot up here in the mountains so I don't want to add more fuel
unless you need to know the amount I used but it looks like 5 or 6 gallons.

Re: Fuel Flow sensor Install

by Bill Hertzel » 6 years ago

Bill Hertzel

13 1.95k 8k

Well, it is safe to say that the engine is NOT actually using more than 10gph.
If you indicate 4.7gph Engine OFF and if we subtract that number from your data we get...

2000rpm = 2.2gph
2500rpm = 2.8gph
4000rpm = 5.0gph
5200rpm = 6.3gph

That still seems a little high but more within reason. (Calibration Issue?)

Assuming a rectangular fuel tank; 22gal - (22 x 3.88" / 4.75") ≈ 4 gallons.
A reasonable number.

You did not report the displaying with the senders disconnected but it appears you are displaying the Total Flow without subtracting the Return Flow.

The objective at this point is to get the system to display ZERO Flow with the Fuel Pumps ON and the Engine OFF.
I would look at the Installation/Configuration of the FP-5L

Now the Big questions...
Are you sure you have two senders?
Are you sure they are FT-60s?
How are they connected to the FP-5?

I can find nothing online about how to connect an FP-5 to a fuel injected engine or any engine with bypass fuel flow for that matter.
As far as I can see, it is a single sender computer.
Can you post the installation documentation? (Not the Operators manual!)
We need to see the wiring diagram.

---

Bill Hertzel
Rotax 912is
North Ridgeville, OH, USA
Clicking the "Thank You" is Always Appreciated by Everyone.

Re: Fuel Flow sensor Install

by Robert Hannigan » 6 years ago

Robert Hannigan

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Ok I will look for the install manual. this unit was installed by someone else to provide fuel pressure for the injectors.