Fuel displaying 100% all the time

[GUS]

We have a new Sea Vee29 fully outfitted with Furuno, LOVE IT.

One, hopefully setup issue we have is the two TZT12F screens only display the fuel tank capacity(programmed 117gallons each) (at 100%) and not the actual amount.

We have the Mercury Vesselview 502 and speed & tack smart gauges with twin 400s.

The Furuno screen also show correct fuel burn. this information comes from the Mercury electronics, I don't believe I have tank level sensors.

12.5 in the Furuno Operator's Manual states "This equipment can calculate the remaining fuel from the total fuel and the fuel comusumption rate. This function requires the NMEA Sentence PGN127489 (Engine Fuel Rate).

Can this be my issue and if so, how do I check for or add this sentence???

 

[Johnny Electron]

If you don't have tank sensors it sounds like someone might have put in the wrong fuel capacity unit the "manual fuel management" under the initial setup. If you are getting fuel rate and the manual fuel management is "ON" then it should work. There are several ways to see if you are getting the PGN. This normally done with a PC and a NMEA 2000 interface using something like Maretron analyzer software. There is a NMEA port monitor in the service mode of the NavNet but it can be a little harder to understand but that is an option also.

 

[GUS]

Thank you Johnny.

Since writing this post, I found a Furuno document "Manual Fuel Management" for the TZT2.

I'm not sure I am following this exactly, but, would it generally or absolutely apply to TZT3?

 

[Johnny Electron]

Yes, it works exactly the same.

 

[WWolfe]

New to the Forum and have a question relating to running manual fuel management. I have ran fuel management in manual for over a year and recently it stopped working. I'm getting data from my Suzuki's with all the all the information it usually had. including GPH, MPG, RPM etc, but in manual mode on it doesn't calculate. In the past it gave me FDTE and Average Fuel Economy and others. What seems weird now is in manual mode under network sensor it shows Manual Fuel Management but is greyed out and both of my engines are under can bus but are also greyed out and it doesn't allow me to turn them on. What should be showing and if this is correct how do I turn them on?

 

[Johnny Electron]

Manual mode is only for systems that don't have real tank sensors in place. One should use the real data if available. If manual mode is wanted, the real sensors would need to be disconnected. Can't have both.

 

[Quitsa]

Manual mode is only for systems that don't have real tank sensors in place. One should use the real data if available. If manual mode is wanted, the real sensors would need to be disconnected. Can't have both.

I am puzzles by your statement. My boat has NMEA 2000 tank sensors. The TZT 3s see this data and will display it on instrument pages. However, I prefer to use the manual fuel mode because it is more accurate and not subject to the tank level changes caused by the boat’s attitude. It works fine. As long as “manual” is selected in the engine and tank setup, it is possible to use it even with tank sensors. Maybe I misunderstood?

 

[Johnny Electron]

Maybe they changed it in the software but in the past if you had tank sensors you had to use them. Real sensors are expected to be better than estimates. If it works for you in manual, I can only guess they have made some changes with the most recent updates.

 

[Quitsa]

Maybe they changed it in the software but in the past if you had tank sensors you had to use them. Real sensors are expected to be better than estimates. If it works for you in manual, I can only guess they have made some changes with the most recent updates.

Thanks. I think on a boat that has electronically controlled engines that provide live fuel consumption data with 2-3% accuracy, the manual fuel management is far more precise if you take care to alway adjust the fuel level when you add fuel to the tanks. My tank sensors are pretty accurate at the dock. With even 2 foot seas rolling or pitching the boat a bit, the readings bounce up and down. I'm a big fan of manual fuel management!