So I fill up my tank to completely full and then after about an hour or so the gauge goes to around half then a little later is goes to empty. Any thoughts on this? I know there is plenty of gas in the tank well more then half or empty.
So I fill up my tank to completely full and then after about an hour or so the gauge goes to around half then a little later is goes to empty. Any thoughts on this? I know there is plenty of gas in the tank well more then half or empty.
Could be a couple of things like the sending unit for your gauge. Those do go out from time to time. Mine in my '08 would go from full, to the gauge bouncing from empty to full eratically, to straight at empty within me burning about 5 gallons from being full. The sender is in the tank and is not the easiest thing in the world to change.
The other thing to know is that due to the design of those tanks which is in the shape of an L the gauge will never be completely accurate. The first half will burn off well before the second half. They just never really found a good way to fix this until they started putting the digital 'flow' type of gauges in the new Evo's.
Jason Phillips
I have the fuel flow for my nmea network so I think I'm just going to fill my tank again and configure my LMF400 gauge for the tank configuration and I will just use that for now on
I figured it wouldn't be an easy fix since these tanks are not easy to get to.
Thanks
You should be able to access that tank within a matter of minutes with a cordless drill and a philips bit. You may not even have to remove the seats to work on the fuel sender. To disassemble the whole seating area on my 04 295 and have complete access to the fuel tank can be completed in probably ten minutes, a little longer to reassemble. Don't be afraid of it, it is rather simple.
IPS,
I have a '93 295 pro with a similar problem. Some posts and the C&O service team pointed me toward the ground wire for the sending unit as the culprit. If that isn't it, do you have any actual fix that you did which you are willing to share? I have the tank exposed and can get to both the sending unit & the grounding wires easiily, I just don't quite know what the next diagnostic step is.
Fiat Voluntas Dei!
It turns out it was the ground wire for the sending unit. Thank you to everyone who responded.
MEckl8321:
There is a way to test the gauge, a few resistors or a decade resistance box will be required. The fuel sender can also be tested and a VOM will be required.
I found this next paragraph on another website:
Most marine fuel senders have a resistance of 33ohms to 240ohms. Using the gauge as your guide, the VOM reading on the resistance scale should indicate 33ohms with a full tank, 240ohms at empty and somewhere between 80ohms to 120ohms when half full.
Disconnect your fuel sender wires and connect the resistors from the previous paragraph one at a time to the wires and watch for gauge response. If gauge does not respond, it's junk. If it does, the gauge is fine. You can then remove the fuel sender from the tank and ohm the fuel sender with a VOM. Move the arm up and down. You should see a change in resistance similar to the resistance values listed, they probably will not be exact.
Resistors will be available at Radio Shack or a local electronics shop. I would assume 1/8 watt should be sufficient. You may not get those exact values because resistors are not made in one ohm increments. Just get close and that will be fine.
Might be simpler way like a short and open across the input and the gauge will go upscale or downscale. Not sure at this moment but I know the resistors or decade box work, I have done it.
Good Luck
Mike
Modified by BigOne at 7:46 AM 11/12/2009
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