Inaccurate Direct Fuel Measurement

[Dcsqatar]

I have a 2020 R29S with Volvo D4. Since delivery last July, the direct diesel tank measurement has been way off. Basically it only drops below full when the tank is in reality less than 1/2. I have discussed this with the Ranger team a few times and their answer is consistently that I should not worry but rely instead on the Garmin computed fuel remaining. I have found the Garmin computed fuel level to be accurate, but nevertheless I would feel better with a direct measurement as backup.

I followed the procedure for “Full Fuel Tank Calibration” in the Volvo Manual (pg 130) but it had no apparent impact. There is also a “Multipoint” calibration procedure that I did not try as it is more complicated. I discussed this with a Volvo tech from Pacific Power, and he thought it could possibly be due to incorrect specification of the fuel sensor in the Volvo ECS. Within the ECS it is specified as 250 - 30 ohm. I confirmed with Kenny that this is correct for the installed sensor.

My neighbor has a 30 ft Cutwater with a Volvo D6 and he has the same issue. Has any one else experienced and solved this? Maybe I just need to run the tank nearly out and do the multipoint calibration?

 

[tdellaviola]

I have a C30. Yes I go by the Garmin for fuel as it is most accurate. I look at the fuel gage as a thumbnail estimate as it does not seem to show reality, plus as you would expect bounces all over the place depending on the pitch of the vessel.... as long as its not sitting on empty I am good.

 

[BB marine]

I posted a thread on this subject.
viewtopic.php?f=18&t=10780&hilit=+fuel+gauge+calculations#p74140

I find it is accurate after 10 gallons of fuel is used from a full tank.

Two screen shots comparing the Garmin to the Volvo EVC




I asked the Volvo dealer where I stored my boat why the EVC fuel gauge is so inaccurate. He responded its not. The boat manufacture needs to calibrate it at the factory and it is very accurate. He said once in a while they miss and we have to do it. He explained how to do it. The thread shows my procedure. It takes about 5 minutes to calibrate once the calculations are done. It is not accurate when the boat is running at semi-displacement speed. The sending unit is in the aft portion of the tank. When at 2000rpm or less it reads within 1 to 3 gallons of the Garmin.