Fuel Gauge needle Bounces 1/2 a tank.

[Ghost21]

Hello Everyone,

In the never ending project that is a boat. My fuel guage was broken and I would tap it then it would move to where it thought it was supposed to be. I replaced the Fuel gauge and now as the boat rocks side to side the guage bounces about 1/2 a tank. Plus to add to the frustration when I'm filling the tank it takes forever and if I fill too fast it shoots back at me .. Almost got it in the eyes trying to watch for it so it didn't. Plus It never really shows me a full tank on the guage. All of the sudden it started spilling out of the overflow and I was oh.. it must be full..

1. If the needle bounces around I think hey I have 3/4 then look back and think crap now I only have 1/4 tank..
2. Its hard to tell when its full and its a pain the the but to fill what can I do ??
3. Thank you..

 

[muc]

Re: Fuel Gauge needle Bounces 1/2 a tank.

1. The needle bouncing around might be the gas sloshing in the tank or could be a bad sender in the fuel tank. The sender can be removed for testing --- with an ohm meter connected you can move the float up and down while watching the meter --- should be around 30 ohms with float all the way up and 250 ohms with float all the way down and the numbers should change smoothly as you move it. If you do remove the sender make sure you test for gas leaks after reinstalling it --- gas leaks are dangerous.
2. Is the boat level when filling? That can cause a problem.
The fill and vent hoses should have a constant slope towards the tank. Any dips in either hose will cause trouble.

 

[Ghost21]

Re: Fuel Gauge needle Bounces 1/2 a tank.

1. The needle bouncing around might be the gas sloshing in the tank or could be a bad sender in the fuel tank. The sender can be removed for testing --- with an ohm meter connected you can move the float up and down while watching the meter --- should be around 30 ohms with float all the way up and 250 ohms with float all the way down and the numbers should change smoothly as you move it. If you do remove the sender make sure you test for gas leaks after reinstalling it --- gas leaks are dangerous.


--- The hose at the back I think has a small upward curve as it runs from the back down to the bilge area under the fuel filter almost level with the top edge of the oil pan then into the tank.



2. Is the boat level when filling? That can cause a problem.
The fill and vent hoses should have a constant slope towards the tank. Any dips in either hose will cause trouble.

-- The vent hose is a downward curve almost the whole way.


Thanks for the info on the ohms as that will help alot.. Now to find out what a sender unit costs for a 1979 - 18.5' Glasply W/ Volvo penta aq130d. I don't even know the size of the tank..

 

[tpenfield]

Re: Fuel Gauge needle Bounces 1/2 a tank.

As mentioned, it could be the sender is a bit sloppy.

However, it could be that the tank does not have proper baffles to reduce the sloshing around that is normal with boat movement.

Isn't looking down at a fuel fill spout while refueling kind of like looking down the barrel of a gun to watch the bullet come out?