Finley Atherton
Well Known Member
Ever since day one I have had fuel flow readings that vary considerably. I have tried various transducer locations including between the carb and the engine driven fuel pump, between the electric pump and the gascolator and between the fuel selector and the electric fuel pump (the current location). I have replaced the engine monitor and the transducer (under the free exchange offer by JPI on VM 1000C units) with no improvement.
Lately I have discovered that the fluctuations are greatest in turbulence and mainly occur with the small G force changes. Today I went flying in smooth air and the readings were reasonably steady at 5.6 g/h. A mildly aggressive but brief pull on the stick momentarily decreased the reading to 3.5 g/h and a similar push on the stick shot the reading up to 13.8 g/h. The same maneuvers with the boost pump on gave similar results; from about 7.7 g/h down to 3.9 g/h and up to 19.8 g/h
Is this normal? Do others experience these fluctuations? Any suggestions would be appreciated. About the only thing I can think of is perhaps the carb float may be partially filled with fuel and the G forces are causing it to rise and fall, however the readings are the opposite that I would expect with changing G force. The engine always runs perfectly through the fluctuations and has never shown any signs of flooding or leaking fuel from the FAB drain hole.
Fin
9A
0-320, VM 1000C (new version)
Lately I have discovered that the fluctuations are greatest in turbulence and mainly occur with the small G force changes. Today I went flying in smooth air and the readings were reasonably steady at 5.6 g/h. A mildly aggressive but brief pull on the stick momentarily decreased the reading to 3.5 g/h and a similar push on the stick shot the reading up to 13.8 g/h. The same maneuvers with the boost pump on gave similar results; from about 7.7 g/h down to 3.9 g/h and up to 19.8 g/h
Is this normal? Do others experience these fluctuations? Any suggestions would be appreciated. About the only thing I can think of is perhaps the carb float may be partially filled with fuel and the G forces are causing it to rise and fall, however the readings are the opposite that I would expect with changing G force. The engine always runs perfectly through the fluctuations and has never shown any signs of flooding or leaking fuel from the FAB drain hole.
Fin
9A
0-320, VM 1000C (new version)