fuel gauge

[wallydc2]

I have a1991 regal boat with a 3.0 l mercruiser IO. Last year my fuel guage worked, this year when I filled it up it stays on empty. If I hit a wave it moves to 1/4 then back to E. When I turn on the key it moves to E, so I think the guage is working. Could it be the sending unit in the tank since I did not fill it up before storage last year? Or where should I start trouble shooting?

 

[ifallsguy]

Re: fuel gauge

Sounds like a stuck float or bad fuel sending unit. You could check the fuel gauge by shorting the power lead to ground. Don't hold it too long since the gauge wasn't designed to be hooked direct to ground.

If the gauge pins on the full side, it's the sending unit. These are fairly cheap and easy to replace. You can remove the gauge and test it by moving the float and watching the gauge for movement. But my guess is the float is fuel logged and heavy.

When replacing (or reinstalling) be careful not to strip the tank or damage the gasket (fuel leaks).

I've replaced the sending unit in my boat, took about 15 minutes taking my time. And don't do it with a full tank. You don't want fuel leaks.

One other option is to install a flow meter into the fuel line. That is more exact, you can track your usage and find that sweet spot for the throttle to maximize your fuel savings. And most can be hooked up with your GPS, giving you the display there.

Hope that helps.

 

[wallydc2]

Re: fuel gauge

I tested the sending unit by hooking up to ground and the gauge only went to half. Question, on top of the sending unit it has one wire dead center and two wires connected to one of the bolts, Just to be sure, which is ground?

 

[Silvertip]

Re: fuel gauge

The one in the center is the "sender" signal which goes up to the gauge. The other two wires should be connected to the shell of the sender. One goes to the fuel filler (static elimination) and the other to the NEG terminal on the battery or the engine block. Do a SEARCH. I've posted the wiring of a fuel gauge dozens of times. Several times in the last 10 days. If you don't know how to search, scroll through the FUEL GAUGE posts.

 

[wallydc2]

Re: fuel gauge

Thanks for your help. my next question is how do I chose a sending unit. My fue gauge is a faria probably original eqp on my 1991 Regal.