Mark Henderson
Well Known Member
Today was to be the first flight of N815W. As I taxied out to the runway the low fuel pressure alarm started going off. I had had an issue with this a few days ago, and thought it was resolved. I have verified that there is no blockage of any fuel line. The screen in the gascolator is clean. The fuel valve was fully open. Yesterday I had a consistent 3.3 psi of pressure. I parked the plane in the hanger for the night. I added 5 gal of fuel.
Today the pressure fluctuated between 1.5 and 2.7 PSI. Engine speed made no difference. The pressure would drop and the alarm would go off. After a few seconds the pressure would rise, then drop. In case it might be a blockage in the fuel vent, I had a friend pull the fuel cap off as I sat there. No change.
I taxied back to my hanger and pulled the top cowl. Nothing looked amiss. We disconnected the VA-216 fuel line from the sender and turned on the master. There was a good fuel flow, although I had no idea what the pressure was. After reconnecting the line I had 3.3 PSI with the engine running. After a short taxi it dropped to 2.7-2.8 PSI for no reason, then came back to 3.3 or so. There does not seem to be any rhyme or reason to the fluctuation. It was too late to find a mechanical fuel pressure gauge today. I have read other posts, and it sounds like it could be the Dynon sensor, or air in the line. I don't know why there would be air in the line after purging it 3 days ago.
Does anyone have any ideas?
Today the pressure fluctuated between 1.5 and 2.7 PSI. Engine speed made no difference. The pressure would drop and the alarm would go off. After a few seconds the pressure would rise, then drop. In case it might be a blockage in the fuel vent, I had a friend pull the fuel cap off as I sat there. No change.
I taxied back to my hanger and pulled the top cowl. Nothing looked amiss. We disconnected the VA-216 fuel line from the sender and turned on the master. There was a good fuel flow, although I had no idea what the pressure was. After reconnecting the line I had 3.3 PSI with the engine running. After a short taxi it dropped to 2.7-2.8 PSI for no reason, then came back to 3.3 or so. There does not seem to be any rhyme or reason to the fluctuation. It was too late to find a mechanical fuel pressure gauge today. I have read other posts, and it sounds like it could be the Dynon sensor, or air in the line. I don't know why there would be air in the line after purging it 3 days ago.
Does anyone have any ideas?