Flying_Monkey
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Hey all, flying back my Cherokee 6 from Florida to L.A. now. Its an IO540-K1A5. I have the JPI 900 engine monitor installed.
When I turn the aux fuel pump on, I notice that my fuel flow increases a lot, fuel pressure decreases a little, and EGTs slowly rise. On my previous bird, I had a Jpi 830 and the fuel pump being turned on did not affect fuel flow numbers at all. It seems like this shouldnt be happening.
Example- in cruise I turn on fuel pump to switch tanks and fuel pressure goes from 36 to 33, fuel flow goes from 13.8 to 20, and egts slowly rise. When I turn it off everything settles back to where they were. Immediately after I tested enrichening the mixture and the egts fell. This tells me I was already on the rich side of peak (which I had previosuly leaned to 100 ROP). Since the egts rose when I turned on the fuel pump I thought maybe I somehow I was on the lean side of peak and richening would cause egts to rise but that is not what it is happening.
the fuel flow transducer is fairly accurate to the actual amount of fuel consumed except on the tank we use for takeoff. I suspect this is because the fuel pump remains on for awhile and the transducer says we are using more fuel than the engine is actually using. All of the other tanks use a tiny little bit more in reality than the transducer and fuel flow indicate. Except for the tank we use to depart. This leads me to believe the engine isnt actually getting this increased amount of fuel (along with the egt rise).
I dont know enough about the fuel system or the placement of the fuel flow transducer to figure anything beyond this out. Looking for some help. In the middle of the cross country trip and wondering if I should be doing anything about it!
When I turn the aux fuel pump on, I notice that my fuel flow increases a lot, fuel pressure decreases a little, and EGTs slowly rise. On my previous bird, I had a Jpi 830 and the fuel pump being turned on did not affect fuel flow numbers at all. It seems like this shouldnt be happening.
Example- in cruise I turn on fuel pump to switch tanks and fuel pressure goes from 36 to 33, fuel flow goes from 13.8 to 20, and egts slowly rise. When I turn it off everything settles back to where they were. Immediately after I tested enrichening the mixture and the egts fell. This tells me I was already on the rich side of peak (which I had previosuly leaned to 100 ROP). Since the egts rose when I turned on the fuel pump I thought maybe I somehow I was on the lean side of peak and richening would cause egts to rise but that is not what it is happening.
the fuel flow transducer is fairly accurate to the actual amount of fuel consumed except on the tank we use for takeoff. I suspect this is because the fuel pump remains on for awhile and the transducer says we are using more fuel than the engine is actually using. All of the other tanks use a tiny little bit more in reality than the transducer and fuel flow indicate. Except for the tank we use to depart. This leads me to believe the engine isnt actually getting this increased amount of fuel (along with the egt rise).
I dont know enough about the fuel system or the placement of the fuel flow transducer to figure anything beyond this out. Looking for some help. In the middle of the cross country trip and wondering if I should be doing anything about it!
