Source of Fuel Flow Data

[CaspersCruiser]

Someone on my dock today asked the source of the fuel flow data for the Yanmar 4BY2 engine installed in my 2012 R27. I made a quick look through the engine manual, but did not see the answer. Can anybody tell me how the fuel flow is determined? Is it pressure converted to fuel flow? Or is there a transducer? How accurate is the data?

 

[stwendl]

I presume the data is similar calculated by known amount of injections multiplied by the rpm of the engine. The computer must know how much to inject in order to controls the engine. In turn you get the consumption. Flow meters are not useful because there is a return line and you would have to add flow menter there as well. Flow meters are less precise than the injectors unless you have medical metering pump and they don't work at those pressures needed.

On the newer systems the flow rate should be available on the n2k bus as the garmin can display it and the only connection to the engine would be n2k

 

[knotflying]

Not exactly sure how it gets the info. I doubt it is a flow meter, but I found the information to be spot on. You just have to remember to accurately update fuel purchased or press fill tanks button when you get fuel.