Fuel Gage readings

[JB in Alabama]

Hey Guys,
I ran out of gas a couple of weeks ago with 1/2 tank showing.
Joe, who I bought it from in June said he thought the gage was off.
How do I find the problem?
thanks!

[mickmate]

What type of sender/tank is it. Some senders can be calibrated but you'll probably want the tank out and we can talk you through it from there.

[JB in Alabama]

then i'm going to work on the carb first, then come back to this!
thanks!

[dcdoug]

You can calibrate some senders with the tank still in the car or remove the sender and calibrate it out of the tank. For mine I submerged it in a gas can and set one adjustment screw to "full" then took it out dried it off and set the other adjustment to "empty". It is perfectly calibrated. The location of the sender on a CSX is another matter though and means that even a perfectly calibrated guage won't show much of anything until you are at about 1/3 of a tank. When the guage moves, go to a gas station.....

[shelb65]

Check and see if your tank has a fuel form inside, sometime the send unit get hung up on it

[WardL]

There was a fairly widespread corrosion issue in gasoline 5 years ago. The symptoms were the fuel gauge level indicator got corroded and stoped working. This resulted in drivers runing out of gas when their gauge indicated they still had fuel. Different manufacturers used different alloys. The gold alloys never had a problem but the silver alloys would fail. This may or may not be your problem. If you have a choice, replace the internals with a gold alloy.

[mickmate]

You've found the problem it runs out at 1/2 on the gauge! It still runs drive like you own it.

[JB in Alabama]

I just press the trip mileage everytime I fill up now.

I will NOT miss a chance to drive over a silly Gage

My plan is to solve the carb problem first, then the tank........
I really feel I should get a 402 or 427 but that needs to wait a bit

[mickmate]

You prioritise well. Atta boy!

[Blittleton]

JB,

If you have Autometer gauges your sending unit is getting caught on the baffles inside your tank.

If you VDO gauges in your Backdraft you can adjust the gauge by pulling out the gauge and there is an adjustment screw on one of the sides. Empty the tank and adjust to the E and fill the tank adjust to F. Pretty simple.

Bill

[Cashburn]

Cars built around that time employed a sender with an arm and float design similar to this:



They have a nasty habit of "spinning" so the arm reorients itself and is now in contact with one of the internal baffles of the tank. So you either get a gauge that never reads full or always stays above 1/2 or so. You got the above 1/2 scenario.

Have to drain tank and drop it and then see what's up wit the sender and if it needs to be reoriented.

[JB in Alabama]

Thanks!
and a picture IS worth a thousand words!

[Doug I]

Jay - by draining and then dropping the tank are you thinking that that could shake the sender loose from whatever it's getting hung up on?

[madmaxx]

alot were never set right from the factory, empty the tank, drop it, pull sending unit. go to respective gauge website and there will be detailed instructions. the idiots that put mine in bent the rod instead of cutting to lenght.

[Cashburn]

Originally Posted by Doug I

Jay - by draining and then dropping the tank are you thinking that that could shake the sender loose from whatever it's getting hung up on?

You have to know/see about these senders to understand. You can swivel the position of the float arm so it does not contact anything. Also as Max points out it could need shortening.

A new sender is about $25 so it is worth the instructions it comes with to put a new one in.

[Doug I]

Jay - I was just funning you about 'dropping' the tank as in letting gravity win ...
I've spent many hours fiddling with gauges getting them to work. Worst one was a gauge that'd hang on 'full' whenever it went inverted.

[Cashburn]

Oh missed the humor this morning... I was distracted

[Doug I]

my trick is 3 coffee's