Fuel Levels

[whitlock87]

this is why I installed a flue flow gauge. it measure the amount of gas going into the engine.
all I do is reset it to 38 after every fill up and I now with a 1/2 gallon how much I have left

[Stingreye]

I don't think this will work on our engines on account of the way the fuel delivery system works. The fuel rails to the injectors are pressurized and receive more fuel than required. The excess is returned. A fuel flowmeter would be inline and measuring fuel delivered to the rails - this includes fuel consumed and fuel returned. In such a system, the cumulative fuel consumption measurement would be wrong in short order. This is my basic understanding of the setup ... if it's incorrect, please advise.

-Tulsah

When I looked at it after I first bought my boat, PCM has a fuel return to the tank and it requires a more high end flow meter that measures both. The more affordable ones will not work and will be wrong by the amount returned to the tank.

Duncan has a PCM so his meter would likely work for a motor with a return line.

[IDBoating]

The other option is to read the fuel flow data reported by the ECU. All fuel injected engines know, to some degree of accuracy, how much fuel you're consuming because they are controlling the pulse widths going to the fuel injectors. Yes, it won't be 100% dead-on accurate but studies have shown it's within 5-10%, which is good enough for anything but engineering purposes. I have been looking at that data on my engine for some time now. No additional sensors required.

[Duncan]

Tell me more about this. Where does it go in the boat? Which one did you buy?

This thread was the one I looked at in deciding to go with a Flo Scan for engines with fuel return lines. Post #24 in there has a link to a few other threads.

[whitlock87]

On my boat I have the marine power 5.7, there is only one gas line going from the fuel tank to the first fuel pump / filter ( low pressure) I installed my transducer before this pump. But they do offer system that monitor both flue out and flow in

[IDBoating]

On my boat I have the marine power 5.7, there is only one gas line going from the fuel tank to the first fuel pump / filter ( low pressure).

That's probably because your 2004 boat has a carbed engine with a float bowl, needle, and seat. Engines like that don't need to flow fuel back to the main tank since the float bowl acts as an "intermediate tank", buffering between the main tank's supply and the engine's actual demand. Lawn mowers, snow blowers, etc. often work that way. On the other hand, the carbs in our jetskis DON'T have float bowls and as a result they DO have a return line to the fuel tank... that excess pumped fuel needs to go somewhere.

[Z3CO23]

On my 11 RZR I have found that my fuel gauge is somewhat accurate. I have the PCM 343. I have never let it get below 25% because it just scares me to do so. However, based on my 38 gallon tank my fill ups have been pretty close (gallon wise) to what my percentage reading on the gauge says.... not exact but close.

[trent]

The other option is to read the fuel flow data reported by the ECU. All fuel injected engines know, to some degree of accuracy, how much fuel you're consuming because they are controlling the pulse widths going to the fuel injectors. Yes, it won't be 100% dead-on accurate but studies have shown it's within 5-10%, which is good enough for anything but engineering purposes. I have been looking at that data on my engine for some time now. No additional sensors required.

WABoating,
What do you use access that data?

[IDBoating]

What do you use access that data?

A board I designed on which I included a CAN interface, so I can transmit and receive on the engine's CAN network.

I wasn't saying the average boat owner could just splice into it, but rather that a company offering "flow meters" could do so much easier and less expensively by simply taking advantage of the data that is already available.

[trent]

A board I designed on which I included a CAN interface, so I can transmit and receive on the engine's CAN network.

I wasn't saying the average boat owner could just splice into it, but rather that a company offering "flow meters" could do so much easier and less expensively by simply taking advantage of the data that is already available.

Understood, thanks for clarifying.

[Tulsah]

Great info! It doesn't look like I can get away with the $150 I spent adding a flowmeter to my old sterndrive through ...

-Tulsah

[Z1Fan]

Let me tell you guys , the ECU info is more accurate than you know , if you can access it , it's the way to go !!

Sent from my HTC One_M8 using Tapatalk

[lalijaca]

Hey Whitlock87, I also have a 21i with a MarinePower 340HP in it. What was the system you used. I like the idea of a transducer and a remote readout. Was it easy to install? Where did you fit the readout?

[whitlock87]

That's probably because your 2004 boat has a carbed engine with a float bowl, needle, and seat.
.

Nope
I have a GM vortec 5.7 MPFI 335 hp

[IDBoating]

Hmm... then I don't know why you would have only a single fuel line from the tank. Hopefully an engine expert will chime in here (Hello, Dom?). I'd love to know!