Low Fuel Pressure Indication

Its incredible to me that this was posted in 2014 and for almost 10 years none of the many, many folks with this problem saw it or informed anyone else about this easy solution. Shame on Rotax for not bringing it to our attention years ago; they knew we were having this issue and never offered any viable help. I will cut them a LITTLE slack because it is a Dynon/Kavlico problem, but surely they know that thousands of Rotax 912s are monitored by Dynon screens with Kavlico sensors.

Other EFIS systems, such as Garmin, often use the Kavlico P4055-(X) also, so the problem is likely not limited to Dynon equipped aircraft.  Garmin had an SB relating to these sensors possibly leaking, but I don’t think they ever had anything on this issue.  This is one of those things that seems obvious once it’s discovered, but is a very difficult find when diagnosing the problem.  It is strange that it took us so long to come across this. 

I went out today for a flight after disabling the silicone connector seal. Did a hard max performance climbout from 1150' to 7500' altitude and my fuel pressure indication stayed steady at about 3.7 psi thru the whole climb; I don't remember it ever doing this before. It usually varies and often falls below 2 psi. I will watch it for more flights and climbs, but I do believe the cause and answer have been found.

For long term solution I think rather than replace the sensor which is working fine, I will carefully cut a fine groove across the silicone seal to destroy its airtightness, but retain most of its ability to prevent ingression of dust and water.

I am anxious to hear from some others who have been fighting this issue for years, report on their results. 

Its absolutely staggering that Dynon (its not a Rotax issue) have not, (over 9+ years) come up with a seal that will allow the free movement of air in/out of this fitting, so as to normalise with ambient pressure.

I have removed the seal from the plug going into my fuel pressure sensor - its identical to the photo in the advisory document from 2014.

Weather wasn't conducive for a flight yesterday - will report back when I have flown.