RV-12 High Fuel Pressure Readings After New Fuel Pump SB

[Geico266]

Not sure what to make of this. I replaced the fuel pump due to the SB and now I have FP readings in the 5.9 psi at start up, and it settles down to 4.6 in flight. The variations are concerning also, 3.9 - 5 in flight.

I have the original sending unit, but it was rock solid at 4.3 psi with the old pump.

I fly with the electric back up off.

What say you?

Other than that I have about 350 hours on the -12 and it is an absolute delight to fly each and every time.

 

[rejnovca]

Fuel Pressure

I replaced the fuel pump about 18 mos ago after failure of the original pump. Experienced exactly what you described with the new fuel pump and was considering replacing the pressure sensor with the new style pressure sensor from Dynon. Then after about 10 flights the pressure settled back into lower levels and I have had no high pressure alarms since. Did not replace the pressure sensor.

 

[Dvalcik]

Not sure what to make of this. I replaced the fuel pump due to the SB and now I have FP readings in the 5.9 psi at start up, and it settles down to 4.6 in flight. The variations are concerning also, 3.9 - 5 in flight.

I have the original sending unit, but it was rock solid at 4.3 psi with the old pump.

I fly with the electric back up off.

What say you?

Other than that I have about 350 hours on the -12 and it is an absolute delight to fly each and every time.

The rotax-owners.com website quotes the new fuel pumps: 2.18 - 7.3 psi

I also fly with my electric fuel pump off (only one for take-offs and landings)

 

[Geico266]

I replaced the fuel pump about 18 mos ago after failure of the original pump. Experienced exactly what you described with the new fuel pump and was considering replacing the pressure sensor with the new style pressure sensor from Dynon. Then after about 10 flights the pressure settled back into lower levels and I have had no high pressure alarms since. Did not replace the pressure sensor.

Well then, I need to fly more.

 

[Tony_T]

 

[funflying]

Me too!

I just replaced mine this weekend and have one test run under my belt. With the electric on the pressure read 5.0 which put it in the caution area. It had been the caution range at 1.9 with the old pump.

I hope to fly tomorrow morning to test further since I have gotten in only one test flight so far, then the pump issue. I will watch to see how the pressure stabilizes.

 

[funflying]

Looks good

Flew this morning and during the warm up fuel pressure 5.1-5.3, but once I got flying it stayed at 4.9-4.4. This was both mechanical & electric operating. I am good with this since the original pump barely worked and I did the first flight on the electric pump at 1.9psi

Back to the test cards.....

 

[WingedFrog]

I tried to change the limits on the Skyview based on the range provided by Rotax for the new pump. I met a set-up that defines five different ranges going to red low, yellow low, green normal, yellow high and red high. How in the world am I going to figure out what I need to put in each range?

 

[WingedFrog]

Here is is the answer:

I tried to change the limits on the Skyview based on the range provided by Rotax for the new pump. I met a set-up that defines five different ranges going to red low, yellow low, green normal, yellow high and red high. How in the world am I going to figure out what I need to put in each range?

I called VANs about this and here is the answer I got after they had a look at their red RV-12:

range 1, 0.0-0.7 red
range 2, 0.7-2.2 yellow
range 3, 2.2-5.8 green
range 4, 5.8-7.2 yellow
range 5, 7.2-8.0 red

you will also need to change max value to 8.0 and the minimum to 0.0

 

[roger lee]

New fuel pump

The new Rotax fuel pump reads around 4.6-5.8 for most people. Rotax raised the high pressure limit to 7.2 psi.
If you have a new fuel pump you need to have a re-circulation line. You could get away without one with the old AC and Pierburg pumps, but the new pump needs one.