Fuel Monitoring Systems: Lowrance, Floscan, others?

I'm surprised that you didn't get a more definitive answer from Garmin support, I have always found them to be first rate. I don't believe the issue is with fuel injection per se, the issue is that fuel injection systems have a return line to the fuel tank. The GFS10 would measure the fuel returned to the tank as spent fuel and not provide accurate readings.
 
Phlorida said:
I'm surprised that you didn't get a more definitive answer from Garmin support, I have always found them to be first rate. I don't believe the issue is with fuel injection per se, the issue is that fuel injection systems have a return line to the fuel tank. The GFS10 would measure the fuel returned to the tank as spent fuel and not provide accurate readings.
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This is correct. The GFS-10's work incredibly well with my FI engines with no return line. The returned fuel issue is also the reason that the GFS-10 aren't compatible with diesels. I've submitted this issue as a feature request to Garmin, but they don't appear to be interested.

Garmin hasn't done a good job at marketing this product. There's lots of confusion out there about it, and it certainly doesn't help that some of the confusion comes from Garmin itself.

For example, the specified minimum flow rate of 2 GPH is frequently misunderstood. I respect Garmin's intention of lowering expectations of accuracy with low flow, but they way their docs read implies that they DON'T read below 2. My meters never go to zero while the engines are running, and as far as I can tell, do a pretty good job at idle speeds.

The tie-in to existing fuel senders is yet another source of confusion. It's an OPTION. I chose not to do it. What I lose with that in my configuration is an analog representation of fuel level for each tank according to my senders. However, the system calculates total fuel remaining according to the capacity and fill-up data I've given it and gives me 1 analog gauge as well as a digital figure.
 
I have all but given up on my Lowrance Fuel Flow. A few weeks ago, I fill both tanks and set the the tanks as full on the unit. It asked me to calabrate with the engines, I said OK and now it is all screwed up, yet again. To go 13 mile it shows me burning 58gal on the STBD and 13 on the port. Lowrance states I have to do a restart yet again. As far as fuel flow goes it is a POS!
 
The warnings in the installation instructions aren't significant - here is a cut and paste of them in their entirety;

> The GFS 10 is designed for use with gasoline-engine fuel systems. Do not use the GFS 10 with diesel-engine fuel systems. Do not use them with fuel that contains more than 10% ethanol such as E85 fuel.

> The GFS 10 is designed for use with single-line fuel systems. Do not install the GFS 10 on engines with a return line to the fuel tank. On pressurized fuel injected systems, the GFS 10 must be mounted on the low pressure side of the high-pressure fuel pump. Engine mounted fuel reservoirs may cause erratic flow readings. The GFS 10 is not recommended for systems with large engine-mounted fuel reservoirs.

The balance of the warnings all deal with the flammability of gasoline.
 
Thanks to all for their replies. I am buying the Garmin 740S chart plotter with an add-on card called G2 Visioning. The G2 is 299, but they are offering a $200 rebate right now if you buy the chart plotter. The G2 lets you see the bottom structure, like you had a camera under your boat..as well as many other features.
 
Mark - Does that also mean that you have settled on the GFS 10? You won't be disappointed with the 740s, it is a great unit.
 
We have Floscans on our Detroits from the previous owner. I believe they were about $3K or so.
 
AKBASSKING said:
I have all but given up on my Lowrance Fuel Flow. A few weeks ago, I fill both tanks and set the the tanks as full on the unit. It asked me to calabrate with the engines, I said OK and now it is all screwed up, yet again. To go 13 mile it shows me burning 58gal on the STBD and 13 on the port. Lowrance states I have to do a restart yet again. As far as fuel flow goes it is a POS!
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Reset the gauge back to stock and only calibrate if it is off. Mine has been pretty accurate right out of the box with no need to mess with the calibration. I did get into that menu once and changed it by mistake and ended up with results like you stated. Best thing I did was reset back to stock and leave it alone. Even when I run with both engines off of one tank the gauge and sensors work pretty well, was not sure if the sensors would be able to keep up with 2 7.4's drinking through the same hose at cruise...
 
GFS 10s an easy install?

What prices you guys paying for them?
 
I have a write-up of my installation that I'll try to post soon. Some of it was tedious, but overall, not a difficult project. I didn't enjoy hooking up the leads to the dash power and switches. Mine were about $150 ea from BOE several years ago. I bought the NMEA2000 backbone cable locally and already had connectors etc.
 
Have you already placed the order? BOE (site sponsor) has a much better price. Also keep in mind that the while the power/sensor cabling on the units will reach your dash, the GFS-10 doesn't come with a long NMEA-2000 cable. Assuming you plan to build a NMEA-2000 network/bus , you'll need a "backbone" cable to get the data from the ER to your plotter, and depending on what else you're buying and hooking up, possible NMEA starter kit (terminators, T-connectors etc) as well.
 
I have the Garmin 546S with the fuel flow GFS 10 it works great, I do have a 5.0 EFI.So no issues with fuel injection
 
Anyone go them talking to a RayMarine e7d?
 
Bring a bring labeling machine. Skip the fuel sender option at first. (if you want to do it later, you can) Map out your NM2k layout ahead of time, and have an understanding of the terminators, "drop" cables vs. backbone etc. I'm assuming that your senders came with the 3M gelpack connectors. I ignored advice to throw them away, because they seemed so convenient. I had to throw them away AFTER I used them.
 
Phlorida said:
The warnings in the installation instructions aren't significant - here is a cut and paste of them in their entirety;
> The GFS 10 is designed for use with single-line fuel systems. Do not install the GFS 10 on engines with a return line to the fuel tank. On pressurized fuel injected systems, the GFS 10 must be mounted on the low pressure side of the high-pressure fuel pump. Engine mounted fuel reservoirs may cause erratic flow readings. The GFS 10 is not recommended for systems with large engine-mounted fuel reservoirs.
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On my '03 280DA with 4.3 MPI engines, there is a single fuel line going from tank to fuel filter. Then there are two lines; one a high pressure line, and one a low pressure (return?) line. So...would the GFS-10 work for my setup? Seems like it would, but I'd like to confirm with an expert here that it will work.

My engines are Smartcraft enabled, but I do not have Smartcraft displays. I've looked into it, but the cost of getting it is high, and figuring out exactly what I need it difficult from Mercruiser. If I could just go with these fuel flow meters, I'd be happy. I already have a Garmin plotter that supports the flow meters and already have a NMEA2000 setup for my radar to communicate to the plotter.

Thanks,

Tom
 
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Gunn said:
On my '03 280DA with 4.3 MPI engines, there is a single fuel line going from tank to fuel filter. Then there are two lines; one a high pressure line, and one a low pressure (return?) line. So...would the GFS-10 work for my setup? Seems like it would, but I'd like to confirm with an expert here that it will work.

My engines are Smartcraft enabled, but I do not have Smartcraft displays. I've looked into it, but the cost of getting it is high, and figuring out exactly what I need it difficult from Mercruiser. If I could just go with these fuel flow meters, I'd be happy. I already have a Garmin plotter that supports the flow meters and already have a NMEA2000 setup for my radar to communicate to the plotter.


Tom,

I'd be interested in whether it works on your boat as well. I'll have to check out my setup this weekend as I've been wanting to do this install as well. I had the Navman inline flow meters hooked into my Navman 5500 on my boat I'm trying to sell and I really miss having the data.

One question I haven't seen asked is how an onboard generator would be hooked into this system to measure the usage it consumes. Would you need a 3rd GFS-10 installed, or is it easier to just manually calculate that fuel usage?

Mike



Thanks,

Mike
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One question I haven't seen asked is how an onboard generator would be hooked into this system to measure the usage it consumes. Would you need a 3rd GFS-10 installed, or is it easier to just manually calculate that fuel usage?
Mike
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You could install a meter for the generator and configure it as "3rd engine", but the draw is well-below Garmin's minimum of 2 GPH, so the accuracy would be questionable.
 
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