MEP-803A Fuel Gauge issue

[Browning1]

When I purchased my MEP-803A it showed 1/4 tank of fuel on the gauge but would not start due to the no fuel light was on. Put 2 gallons in it needle moves between 1/4 and 1/2 tank and it fired right up. Fast forward a month as I'm load testing it the needle moves to 1/4 tank and generator shuts down and no fuel light is on. What would be causing it to show 1/4 tank but out of fuel. I know the float is not stuck since I had all that out and moving freely when I replaced the fuel well nuts.

 

[rickf]

Does it show full when it is actually at 3/4? May need calibration or it may simply be a bad sender.

 

[2Pbfeet]

Are you sure that the float moves freely and isn't binding in the tank?

If there is residue (gunk) on the sender it may not work well. A little carb cleaner goes a long way. I think that it is always worth checking the gauge values while moving the float outside of the tank and making sure that the values move in sync with the float movement. I've seen floats move smoothly but generate erratic values due to the contacts being grungy/gunked up.

All the best,

2Pbfeet

 

[Browning1]

I will have to check to see about float movement in relation to the gauge reading. Yes the float does move freely and isn't binding in the tank.

 

[Scoobyshep]

Never worked on this specific model, but I have had floats get stuck and also leak to the point where they don't float correctly.

 

[Toolslinger]

As I understand it, the fuel gauge has nothing to do with the no fuel fault light. You may be looking at a sketchy gauge sender, and then the low fuel float is out of calibration, or sticky...

 

[DieselAddict]

It is possible that the float is binding or the sensor on the float is bad/dirty. The stalk can be turned in its mount so it could be a simple problem of it not being oriented correctly in the tank.

The low fuel float is on a separate stalk. The same comment does apply in regards to orientation.

There is a step in the bottom of the tank that can cause issues if the stalks are not oriented correctly.

You can pull the screen out of the filler neck and reach in to feel how everything is oriented and if anything is binding.

 

[Ray70]

Unless I'm reading wrong, you didn't really say for sure if you are actually out of fuel or simply the low fuel light came on but the gage says 1/4 tank and there really is 1/4 tank left.

If the gage says 1/4 but you really are almost out of fuel, perhaps the sending unit is set wrong?
The original style sending unit the is made up of 2 halves with a sliding adjustment in the middle that adjusts the overall length as well as an adjustment to change the length of the float arm itself.
One or the other could be incorrect ( setting the float too deep ) making the gage read incorrectly.

If the light came on and you really do still have about 1/4 tank left, that would be an issue with the dual float assembly, which controls the fault light, not the fuel level sending unit.

The dual float assy. controls the aux. fuel pump and the low fuel light.
The the other mechanical fuel sending unit with the float arm and rheostat mechanism controls the gage itself, not the light.

 

[Guyfang]

Would be much easer if everyone called the things what they are.
Low level fuel switch: FL1
Aux Electrical Fuel Pump Float Switch: FL2
MT5: Fuel Level Indicator
M5: Fuel level Indicator, (Meter)

The meter shows 1/4 tank. But what is really in it?

 

[rickf]

Unless I'm reading wrong, you didn't really say for sure if you are actually out of fuel or simply the low fuel light came on but the gage says 1/4 tank and there really is 1/4 tank left.

If the gage says 1/4 but you really are almost out of fuel, perhaps the sending unit is set wrong?
The original style sending unit the is made up of 2 halves with a sliding adjustment in the middle that adjusts the overall length as well as an adjustment to change the length of the float arm itself.
One or the other could be incorrect ( setting the float too deep ) making the gage read incorrectly.

If the light came on and you really do still have about 1/4 tank left, that would be an issue with the dual float assembly, which controls the fault light, not the fuel level sending unit.

The dual float assy. controls the aux. fuel pump and the low fuel light.
The the other mechanical fuel sending unit with the float arm and rheostat mechanism controls the gage itself, not the light.

Ray, he did mention it ran out of fuel while doing a load test. while showing 1/4 tank and then light came on. Sounds to me like the the light is correct and the gauge is not.

 

[Guyfang]

There is a difference between running out of fuel and the FL switch shutting the set off for no fuel.

 

[Ray70]

There is a difference between running out of fuel and the FL switch shutting the set off for no fuel.

Correct!
It shut down due to the low fuel indicator, he didn't physically run out of fuel.
But what we don't know is if he had 1/4 tank and the indicator light is wrong, or was he really almost out of fuel and the indicator is right but the gage is wrong.

 

[rickf]

THAT is why I like my old 00X machines. No electronics to tell the machine what to do other than an overheat switch and and oil pressure switch. Both very easy to check/bypass if needed.