Gagarin737
Well Known Member
Before I open the fuel system once more I hope someone will come with a solution/things to check.
A few flights ago I had one drop of fuel pressure during cruise. Pressure dropped from 4,5 to 0,7, lasting 10 seconds. Pressure recovered in a few minutes. During the climb out after a low pass 10 minutes later the pressure dropped to 0,2psi. Rest of the flight normal values. All flights before I had a constant pressure of 4,5 in all flight phases.
I changed the fuel pump (still had the old one, not leaking) and replaced the sensor for a "Kavlico" sensor.
Test run thereafter didn't show any problems, steady pressure around 4,5 with both the electrical and mechanical pump, 4 with only the mechanical (engine off pressure is around 2,5).
During the flight thereafter I had a pressure drop during climb out to 0,2 , lasting 20 sec. Pressure climbed back slowly up to 5 psi after 45 minutes flight. The flight thereafter on the same day gave me a minimum pressure of 2,5 during climb out, normal pressures for the remainder of the flight.
Last flights the same problem; first flight very low pressure, flights thereafter on the same day no problems.
I checked the gascolator, totally clean, and did an other flow test. Flushed all fuel lines after the gascolator (bit redish fuel from the pressure line).
Fuel flow values are constant during the pressure drops, engine is running fine. Pressure drops occurs after giving power. In case of pressure drops due to supply problems I expect to see fuel flow will drop as well but I don't see that.
I forgot to download the last flight, will post that next week.
-Next step will be a mechanical gauge to check the digital values.
-Checking the finger screen in the tank
-checking the fuel valve
Any more suggestions?
A few flights ago I had one drop of fuel pressure during cruise. Pressure dropped from 4,5 to 0,7, lasting 10 seconds. Pressure recovered in a few minutes. During the climb out after a low pass 10 minutes later the pressure dropped to 0,2psi. Rest of the flight normal values. All flights before I had a constant pressure of 4,5 in all flight phases.
I changed the fuel pump (still had the old one, not leaking) and replaced the sensor for a "Kavlico" sensor.
Test run thereafter didn't show any problems, steady pressure around 4,5 with both the electrical and mechanical pump, 4 with only the mechanical (engine off pressure is around 2,5).
During the flight thereafter I had a pressure drop during climb out to 0,2 , lasting 20 sec. Pressure climbed back slowly up to 5 psi after 45 minutes flight. The flight thereafter on the same day gave me a minimum pressure of 2,5 during climb out, normal pressures for the remainder of the flight.
Last flights the same problem; first flight very low pressure, flights thereafter on the same day no problems.
I checked the gascolator, totally clean, and did an other flow test. Flushed all fuel lines after the gascolator (bit redish fuel from the pressure line).
Fuel flow values are constant during the pressure drops, engine is running fine. Pressure drops occurs after giving power. In case of pressure drops due to supply problems I expect to see fuel flow will drop as well but I don't see that.
I forgot to download the last flight, will post that next week.
-Next step will be a mechanical gauge to check the digital values.
-Checking the finger screen in the tank
-checking the fuel valve
Any more suggestions?