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View Full Version : Why is my fuel gauge showing only a quarter to half full when it is totally full



desertislander
17-10-2015, 11:46 AM
A little teathing problem with my Suzuki fuel dial. I decided to go with analogue guages rather than digital for my new 140 4 stroke, I just don't like the look of the square digital dials, not to mention the frustrations of touch screens etc.. I am thinking that when I had the inside of the tank hi pressure cleaned on change over the float stalk might have been bent a bit. ( It was never taken out for this job ) :-?

Anyway, before I do remove it to try and figure out what it should be straightened to (and even if it is that kind of float) what do I need to look out for and is this the correct procedure. It's the original 2002 Signature floor tank .
Thanks again

Noelm
17-10-2015, 11:53 AM
A couple of possibilities, the sender (float) is shagged, wiring is shot, tank is not full, or the new gauge needs to be calibrated somehow!

tropicrows
17-10-2015, 01:11 PM
I have the same type of game on my boat...they are bloody hopeless. I use the fuel info from the engine and that's linked into my gamin gps where you can setup tanks etc.

tropicrows
17-10-2015, 01:13 PM
Gauge not game.

Flex
17-10-2015, 02:54 PM
Most likely a bent plunger rail and your puck is getting stuck 1/4 way up.

if it's a new 4 stroke you would be mad not to link it up to a nmea 2000 backbone and feed the engine fuel data straight into your gps. It's about 2-3% accurate and you can setup virtual fuel tanks in your gps. Plus you can work out most efficient cruise speeds for your boat.

woukd probably work out cheaper than pulling your tank and installing a new fuel gauge as well.

desertislander
17-10-2015, 04:58 PM
Now that sounds like a great idea Tropic and Flex, but I am not quite sure how I go about it. The only other instrument I have on there is my Humminbird Matrix 97 GPS which I think probably dates from when the boat was new in 2002, so I doubt it would have the capacity for that kind of thing, How about linking it to my Ipad, could that be done?
I guess this the kind of thing you mean http://www.albacombi.com/ although I would be happy with something smaller (and cheaper) just so that I can keep an accurate watch on my fuel (back to google)
Here we go, this looks a possibility http://www.maretron.com/products/tlm150.php



Most likely a bent plunger rail and your puck is getting stuck 1/4 way up.

if it's a new 4 stroke you would be mad not to link it up to a nmea 2000 backbone and feed the engine fuel data straight into your gps. It's about 2-3% accurate and you can setup virtual fuel tanks in your gps. Plus you can work out most efficient cruise speeds for your boat.

woukd probably work out cheaper than pulling your tank and installing a new fuel gauge as well.

Darren Mc
17-10-2015, 05:40 PM
Is this dodgey fuel reading when the boat's on a trailer or in the water?

desertislander
17-10-2015, 05:49 PM
Both Darren

scottar
17-10-2015, 06:22 PM
I suspect the above posts are more referring to using an actual flow reading from the engine rather than an analogue sender to NMEA converter. Any marine gauge that relies on a float type sender tends to be inaccurate due to movement of the fluid - this will affect the nmea ones as well. The other way, it is the actual flow rate of fuel output by the engines computer that is monitored and as such it is not affected by movement.


Unfortunately, as you suspect, your Humminbird is too old and does not have the capability. To do things this way will involve the purchase and installation of a Suzuki NMEA2000 engine interface, a NMEA starter kit and a compliant display. The best option for a display with these engine interface units is a Lowrance as the engine interface is made by them and they are (unless things have changed recently) the only manufacturer that has the calibration software for the interface in their unit. If you choose a different brand of compliant display, your dealer has to do all the programming. All up costs to put this together will be the best part of if not over $1000.00 at a rough guestimate. There are apps but unless you can find one working somewhere and have a play I wouldn't go down that route. You will still need a heap of hardware to make an app work - nmea2000 to wifi - which may require a pc as a server - all too hard in a small boat.


Provided you are happy with the accuracy and are only after a rough fuel level it will (should) be substantially cheaper to rectify your existing set-up. Given the high pressure clean I would be removing and visually inspecting the fuel sender as a first step. As Noelm has posted there are several things that can be wrong - anywhere between the sender and the gauge. Next I would confirm the required resistance range for the gauge, then check you get that resistance by removing the probe and checking with a multimeter as the sender is cycled from full to empty. If this checks out, then continuity test the cable. If all these test ok, and the gauge is being provided the correct voltage (confirmed with multimeter to rule out power supply issues - bad connection etc) then a new gauge is the next thing to try.

Given of course that the motor and installation is brand new, it may just be easier to wait until you take it to John for it's 20 hour service if you are not real good with electricity. If you do get in and have a play, just make sure the power is off when you have the sender out of the tank if you have it disconnected.

desertislander
17-10-2015, 07:26 PM
Thanks Scott, as always, a very thorough explanation, much appreciated. I will wait until I have run down the fuel to almost empty and then check the sender. (and I guess carry a spare 20 It jerry of fuel incase I over estimate what I have left)

EdBerg
21-10-2015, 07:52 PM
There can also be a problem in that the guage that you have installed does not match the Ohm resistance of the sender unit in the tank.

scottar
21-10-2015, 08:31 PM
Edberg is correct. There are two types - American and European. Another thing to consider is the type of tank. I actually hooked my gauge back up yesterday - I hadn't bothered with it previously due to having fuel flow measurement as well. Not only was the gauge set incorrectly (BRP Commander gauge will work with either sender type) but the poly fuel tank has bowed as it expanded (normal from the paperwork). As such even when the tank is as full as the breathers will allow there is an air pocket above the fuel and the gauge will not show above 70 odd percent. The sender and gauge are ok as when the sender is removed the reading will vary anywhere between full and empty.

Fed
22-10-2015, 05:55 AM
A Euro style sender connected to a US style gauge will do that.
111250

Also note the Full/Empty Vs Resistance reversal, no amount of wire swapping can fix that either.

GBC
22-10-2015, 08:13 AM
Have you been to Fraser recently and had fuel left over in the boat and decided to fill up your ute from the boat using a jiggler syphon and accidentally ripped the brass end off the syphon with the sender unit and jammed the sender in one place and had a syphon head rolling around in your ally fuel tank for years after driving you insane? Just another possibility. Don't ask.....

desertislander
22-10-2015, 08:25 AM
Thanks Fed, just to clarify, are you saying that if I use my original Mercury fuel gauge as apposed to the new Suzuki one it should work as before or just replace the sender with a new european style one to achieve parity? Perhaps Suzuki have a compatible sender anyway, will check with them.

Fed
22-10-2015, 09:49 AM
Suzuki should be able to tell you what the sender specs should be.

I'd expect them to be US style due to the size of the US market & the association with BRP but that's only me speculating.

Did your existing sender used to work on a Genuine Mercury gauge, if so then the sender is US style so that throws all of the above out the window.

desertislander
22-10-2015, 10:22 AM
Suzuki should be able to tell you what the sender specs should be.

I'd expect them to be US style due to the size of the US market & the association with BRP but that's only me speculating.

Did your existing sender used to work on a Genuine Mercury gauge, if so then the sender is US style so that throws all of the above out the window.

I removed all my Mercury gauges since the new Suzuki motor came with all new Suzuki gauges as part of the deal and yes, the sender worked perfectly with the Mercury fuel gauge

desertislander
22-10-2015, 10:26 AM
Have you been to Fraser recently and had fuel left over in the boat and decided to fill up your ute from the boat using a jiggler syphon and accidentally ripped the brass end off the syphon with the sender unit and jammed the sender in one place and had a syphon head rolling around in your ally fuel tank for years after driving you insane? Just another possibility. Don't ask.....

Ha Ha, not quite GBC, but I shall remember not to do this in the future lol

Fed
22-10-2015, 11:18 AM
I think the quickest easiest way would be to ask a Suzuki dealer what the sender resistance specs should be in Ohms at Empty, Mid & Full.

desertislander
08-11-2015, 07:13 PM
OK, sorted, turned out to be a faulty electrical connection, all good now