Fuel Gage Question

And I can't spell right now...Fuel gage problem.....

don't know about the fuel gauge, but I think I read that the resister was to make the temp gauge read lower.

I'm probably wrong though

quote:

Originally posted by geoshanna:
...Connected the gage and it dropped to 50.

That is not a valid test. When measuring resistance of the sender, you can't have gauge connected. You will just be measuring the internal resistance of the system, and that won't tell you anything.

quote:

Turned the key on and the gage was around a 1/4 tank. (Almost correct for the 0 ohmns full and 200 empty spec.

So what is the problem? It sounds like you are getting a correct reading.

If you suspect the gauge, take it / send it to a specialist that can test and calibrate it. North Hollywood Speedometer is a well known shop.
http://www.nhspeedometer.com/

George, the sender is a sliding contact potentiometer. If it reads continuous with a VOM, that as good as it gets. Over time, the windings wear and eventually break creating an open circuit. There is no 'tuning' possible, beyond carefully bending the 14" long swinging arm inside the tank, or replacing the float if it sinks. There's a second contact on the sender that turns on the red low-fuel warning light at around 1 gallon left.

The OEM sender is no longer available for 71-72 Panteras with the fuel feed out of a banjo fitting at the rear of the tank. The late sender for '73- up Panteras that has an integral fuel-out line has been reproduced and is available from most of the vendors. It bolts into ALL tanks and on yours, it gives a second fuel-out port if you ever decide to add EFI. The OEM lines on early tanks often rust through, or plug the non-cleanable filter-cloth on the end of the stock line.

Sorry about the confusion guys, just re-read what I posted. It seems as the the sender and gage agree, but I don't think either is acturate. I can't remember if I ever had to put in more that 12 gallons to make the gage read full. What is the capacity of the fuel cell?

Thanks!

I have put 21 gallons in with the red light on....red light goes out at @ 2.3- 2.5 gallons, but have never completely filled it from dry. this is with the early sender/aluminum tank which came with my car '4280' . have you tried the sender out of the tank[connected to gauge], comparing float level to the tank?check the float to see if it floats /check it off the arm ,also on the arm in a bucket of water.

George,

It's possible that the float arm could be incorrectly bent, or that the float is contacting the tank's internal baffle (or both).

The capacity of the tank is 21 gallons. On one full up, I put 19.7 gallons in my tank. Yesterday, I put in 19.2 gallons.

John

Thanks for the tips guys. I'll try the 5 gallons at a time routine with a gas jug when the light first comes on again.

Thanks!

Maybe if there's enough interest, Thomas Tornblom will build some more of his Fuel Gauge Correctors.
http://www.hax.se/gauge-corrector/

when you say fill it up does that mean the gauge is reading full or literally no more fuel can be added?

I suspect that the fuel gauge is reading more accurately with less fuel. I had the light come on the other day and only added 2 gallons. Drove a few miles then added 15 gallons. the gauge read nearly full but dropped quickly to about half and stayed there for quite a while.
With the light on at 2-3 gallons + 12 gallons should be around 15 or 3/4 but if the gauge starts to read a bit higher, then maybe that's why you think you are getting to capacity.

my boat used to be like this.

The gauge tells you the position of the height of the float. The shape of the Pantera tank is not uniform. Because of that, it will appear that you consume fuel faster at different levels than others. There is less fuel available in the full tank level because of the shape of the tank there and as a result won't seem to stay near full for very long.

The greatest volume is the lower 1/3 and takes the longest seemingly to consume that.

It's positioned in the tank where it can reach the lowest point and the highest point.

You can get another 1/2 gallon or so in the filler neck BUT if you look at where the vent is in the tank, it is lower than the highest point.

I don't fill it past that point. I'm concerned of leakage through that valve. It's held in place by pop rivets and pop rivets are not dependably water tight.

The '80s Pantera vent valve had a check valve in it that acted as a roll over safety valve as well. I think the original just has packing in it?

The float can be "re-calibrated" by bending the rod. When the low fuel light comes on in a Pantera, you do not have much time left. About 1-1/2 gallons in mine. Don't idle on a steep hill at a light, you will run dry.

The pickup is right in the low indentation in the tank where the drain plug is. On level ground it stays submerged but not on a steep grade with the warning light on.



I have the early design fuel tank and the fuel pick up is permanently installed in it. It's just a steel tube and that tube holed through at about the 1/3 level. As a result I'd run out of fuel with still a 1/3 full.

I got a new sender/pick up from Wilkninson that has the fuel pick up on it. I had to recalibrate the float on this one. It would read empty with 1/3 tank. All that meant was bending the rod until it read about right.

Seems like nothing is exactly a "bolt-on" for this car?

good post Doug, thanks