kaweeka
Well Known Member
I've been struggling with aberrant fuel flow readings for the past 2 years. Tom Swearengen and I have batted around multiple ideas without nailing down the cause so I'm throwing this out to the brain trust.
Engine: IO 320 B1A about 800 hours
Injection: AFP FM 100 (older model with the purge valve) plumbed between the servo and flow divider
Ignition: Lightspeed Plasma III
Transducer EI FT-60 (Red Cube)
Fuel flow fluctuates randomly and quite drastically between 0 and 5 gph during taxi.
Fuel flow is ROCK SOLID during full power climb and high power settings running ROP
If I run LOP, I'll get to about 20* LOP 62% power and see about 6.7 gph which is about right for my plane historically. After a few minutes, the ff indication will drift down to 4.8 gph without any loss of poser, change in ANY engine parameters, TAS or MP. (I'm not really burning 4.8 goh at 147 kts.) If I leave it alone, it will correct itself after about 1 hour to 1:10 back to 6.7 gph and remain there.
I rewired the run from the GEA 24 to the transducer, replaced the transducer, tried several iterations of hose configurations (thank you Tom) but nothing changes this odd behavior. I cannot figure out the problem. Here is a link to all my G3x data courtesy of Savvy folks. I'd sure appreciate some insight to this phenomenon.
https://apps.savvyaviation.com/my-flights/4123/f520fec6-e341-4f88-9871-c9a31209f356
I'll answer anything I can to help the diagnosis along. Poor Tom has been along for this ride for too long. He is a saint!
thanks all,
David
Engine: IO 320 B1A about 800 hours
Injection: AFP FM 100 (older model with the purge valve) plumbed between the servo and flow divider
Ignition: Lightspeed Plasma III
Transducer EI FT-60 (Red Cube)
Fuel flow fluctuates randomly and quite drastically between 0 and 5 gph during taxi.
Fuel flow is ROCK SOLID during full power climb and high power settings running ROP
If I run LOP, I'll get to about 20* LOP 62% power and see about 6.7 gph which is about right for my plane historically. After a few minutes, the ff indication will drift down to 4.8 gph without any loss of poser, change in ANY engine parameters, TAS or MP. (I'm not really burning 4.8 goh at 147 kts.) If I leave it alone, it will correct itself after about 1 hour to 1:10 back to 6.7 gph and remain there.
I rewired the run from the GEA 24 to the transducer, replaced the transducer, tried several iterations of hose configurations (thank you Tom) but nothing changes this odd behavior. I cannot figure out the problem. Here is a link to all my G3x data courtesy of Savvy folks. I'd sure appreciate some insight to this phenomenon.
https://apps.savvyaviation.com/my-flights/4123/f520fec6-e341-4f88-9871-c9a31209f356
I'll answer anything I can to help the diagnosis along. Poor Tom has been along for this ride for too long. He is a saint!
thanks all,
David
Last edited: