Fuel gauge problem

She's a '76 Martinique with PCM 351W. Gauges are Teleflex, I'm relatively sure.

We went camping/boating this past week and a wierd thing happened. As I consumed fuel, the gauge went down as I would expect, until finally I got near empty. So I go over to Victoria Harbor marinia, and fill her up with gas. 14.7 gallons later the gas pump quits filling and I screw the gas cap back in then head to the pilot's seat. I turn on the ignition, expecting to see the fuel gauge point to the reassuring "F", but was alarmed when no, it was pointing at roughly 1/4 tank. Just for grins, I take the cap back off, and take a gander inside my now full gas tank, and verify I didn't just pump 14.7 gallons of liquid gold (at the price they're charging) into lake Allatoona. Annoyed, I replace the cap, start her up and head on to the cove the kids want to swim in.

The gauge appears to bounce in response to the fuel sloshing around in the tank but only reads 1/4 instead of full.

I intend to check connections at the gauge and sender, continuity, resistance etc.

I'm thinking it's either a loose connection, or the sender has an issue. Anyone have any other suggestions? Can the sender be bounced out of calibration? How much of a PITA is it to change the sender?

Thanks in advance,
Anthony

Thanks Pete. It looks like you're correct the range should be 33 to 240 ohms.

I assume that the reading should be 33 ohms at full, 240 ohms at empty, correct?

I think I have at least a few inches of clearance between the top tank and the rear deck. I haven't had the rear seat out in a long time so I don't really remember. It's got to have more clearance than the exhaust manifolds on the old Dodge RV. THAT was really tight. It was like someone in Auburn Hills thought "Hey we have these great cast iron exhaust manifolds, lets build a motorhome around them!", but I digress...

It looks like skidim sells a Teleflex sender for <$30. Curiously, they don't sell a gauge.

Anthony,

I wanted to fix mine, but after doing a search on this very helpful forum I came to the conclusion that the guages and senders were not very accurate at all.

I filled the tank with gas and took a wooded dow rod ( Stick) and marked the top wet line of gas with a Sharpe Pen. Then I found the half full mark and quarter tank marks with a Sharpe Pen.

Now I just insert the dow into the tank to see what I have. This works well, but I too need to change my sender. My guage seems to be working in some manor.

I hope this helps,

Donald

Pete,

No I have not. I do have a meter and just recently became more comfortable with the use of it. I will check it out.

Right now the Red Neck Stick in the tank method is doing the job. LOL

Thanks

Donald

Checked the wiring and gauge last night. The gauge pegs out if i briefly short the wire attached to the tank to the top of the wire attached to the sender with ignition on. That means gauge and voltage should be ok. So I guess I need a sender, or a stick.