Fuel consumption reading on DIC

[railbuff]

The displays of fuel consumption on the DIC require inputs of speed (mph) and fuel flow rate (gph). By dividing the speed by the flow rate, the answer will be in mpg. I can see where the speed reading is coming from, but where are the two flow meters, for the delivery and return lines, that provide the flow rate signals.
I can only assume that the computer algorithm used utilises the rate at which the injectors are pulsed. How does it compensate for the spill line fuel returned to the tank?
Would appreciate an answer to this interesting aspect of the Duramax.

[Burner]

I do not believe that there are any "flow meters" in the system. It is a formula derived from RPM, Speed and pulse.... I think. :rolleyes: John Kennedy could probably tell us more.


Burner-------> :D

[Kennedy]

They use the ECM's "Calculated (delivery) fuel rate" which, while potentially open to variables, seems to be highly repeatable, and quite accurate.

[sdaver]

unless your are fooling the ecm with the juice :D dave

[AbqGeorge]

The computer must use a pretty good algorithym.

On a recent 1344.6 Mi trip to Ft. Collins and back, towing the FW at about 70:

Computer said -- 113.3 Gal, 11.9 MPG
Actuals -- 127.53 Gal, 10.54 MPG

Just got "juiced" we'll see how badly that messes up the computer.