Fuel flow meter problem

[beermak]

Hi, since ive bought the boat the flow meter sensor never really worked. It will show during 1 or 2 minutes after you start the engine and then will start droping till 0 and will stay there no matter time or any other factor.

What can i do before replacing the sensor?

Thanks

 

[Silvertip]

Re: Fuel flow meter problem

Ensure the sensor is mounted vertically fo best response.

 

[bruceb58]

Re: Fuel flow meter problem

And the exit needs to be at the top too.

 

[beermak]

Re: Fuel flow meter problem

Its placed vertically and the flow is the correct direction

The flow faces down, this should be the other way?

 

[bruceb58]

Re: Fuel flow meter problem

What flow sensor do you have?

 

[beermak]

Re: Fuel flow meter problem

Ive got this fishfinder with the optional flow sensor
http://www.thegpsdepot.com/th4200sx_gps.htm
http://www.twinsuns-online.com/browseproducts/NAVMAN-Single-Engine-Fuel-Kit.html

The sensor is installed in the exact position as shown in the pic in the second url.

 

[bruceb58]

Re: Fuel flow meter problem

Sure looks like flow should be up.

 

[dingbat]

Re: Fuel flow meter problem

Sure looks like flow should be up.

+1..

 

[Silvertip]

Re: Fuel flow meter problem

Didn't you notice the arrow on the side of the transducer?? It clearly shows flow is upward. A fuel filter is also required in line BEFORE the transducer and the transducer also needs to be isolated from shock and vibration. you cannot have it simply flopping around in the hold or bilge. The turbine wheel inside the transducer has extremely fine vanes and is easily damaged by debris passing through it. That is the same setup, although a different head unit as I have on my walleye boat.

 

[beermak]

Re: Fuel flow meter problem

The transducer is in vertical position, it has an arrow on its shell and its in the same direction as the fuel flow... That arrow faces down and so do the fuel line way. Its inatalled in between fuel filters. Instalation seems to be ok for all i can see

Ill try to get a real pic asap

 

[bruceb58]

Re: Fuel flow meter problem

Without taking off the fuel lines, you need to rotate the fuel flow sender 180? so that the outlet is facing up.

You do see that arrow on the sender facing up right?

 

[Silvertip]

Re: Fuel flow meter problem

There are two issues here:

1) The arrow indicates the direction of fuel flow through the transducer and you apparently have that correct. However,
2) Orient the transducer so that arrow and hence fuel flow, is upward - not downward. Another way to look at this is as Bruce pointed out earlier -- the exit port on the transducer must face upward.

You apparently have things only half-right.

 

[beermak]

Re: Fuel flow meter problem

yesterday i had some time to work on, finally weather has been imposible!

changed the direcction of the arrow, now faces up, and the flow also matches the way it should but im not gettin any reading.

this gauge is a piece of yunk finally, thanks to all who cared!

 

[glenn property of pam]

Re: Fuel flow meter problem

dont quit yet a flow meter can be a little quirky and i will try to explain why. the sensor is designed to read liquid flow it gets real confussed by air flow. when the sensor is installed the arrow has to point at the engine as thats the way the fuel is flowing but and this is a big but....... if the sensor is not orininted so the flow goes uphill then any air entrapped in the system will cause the sensor to miss read.

simply air is lighter than gas so all air bubbles will rush to the top of the pipe past the sensor. if the fuel was to flow downwards then it would wash bubbles down with it then the bubbles will accumulate and go back up the pipe confussing the sensor.

so if its installed correctly allow the engine to run for 5 mins to allow the air to get pushed to the engine then if it still doesnt work try to rebooting the navman as it may have locked up if it is seeing a signal that is out of range from the sensor.

you may have a bad sensor or a bad setting but its always worth testing before replacing

 

[beermak]

Re: Fuel flow meter problem

what i didnt do is restart the navman!

its getting so frustrating this device.. the speed wont show now and the wheel aint stuck! So its gettin a lill bulky and useless. cant read speed, gas and if it ever showed a fish id win the lottery!! only depth.. that the only real function i can get today!

 

[glenn property of pam]

Re: Fuel flow meter problem

check that its getting full 12volts and all the accessory plugs are clean its worth unplugging all the accessorys then adding them back and testing one at a time as a short in a sensor can drag the internal voltage down so no sensors work correctly. after that decied if its past saving


im not sure if theres a repair center and even then im not sure if its worth the cost to have it repaired. if you have decied that its broken then you can tear it to bits as its ready to be thrown away so you can not break it any further. inside you will proberly find boards that are plugged into each other, unplug and spray contact cleaner in the connectors then re-assemble. if you managed to get it back together then test it if not then oh well it was broke anyway

 

[Silvertip]

Re: Fuel flow meter problem

If speed AND the fuel flow are not working properly there is likely a head unit problem, not a sensor issue.