Did I run out of gas?

tvmaster

True Classic
For the first time, I may have run out of fuel.
Also for the first time, the ‘low fuel’ red light under the fuel gauge began to randomly flash.
”Woohoo, it actually works!“, I was thinking. But it never stayed on solid, and instead, it went off.
Then, one mile later, sitting in a drive-thru lane, the car just stalled.
After one or two tries, and a bit of throttle, it started, and gave me enough drive to get to the gas station.
The fillup took 10 imperial gallons.
So, the red light: should it stay on solidly when fuel is this low? And, one mile to engine cut-out? That seems low. Most cars get you one gallon of distance, yes? Which in this case would have been 20 miles.
I got 1/20th of that.
Any chance the sensor in the fuel tank is faulty, or sitting too low somehow? How could you check?
Anyone care to chime in on these circumstances....
 
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My experience with my two X’s is that the low fuel light will start flashing when there is still a couple of gallons of gas still in the tank. The flashing is caused by the fuel float bobbing up and down as the fuel sloshes around while driving. Once the level gets really low, the float is low enough that the warning light contact switch is always closed. I have never had a problem with running out of gas when the light is flashing.
It is possible the sensor is going bad but it sounds like it is working correctly. What may be happening is that considering the age of your car, there may be some sediment that has been slowly building up in the tank over the past 47 years. By the time the float gets low enough for the light to come on, there is just a small amount of gas left because of sediment in the bottom of the tank.
I am pretty sure the tank has a 12 gallon capacity if actually empty, but the fuel pickup is not at the bottom of the tank. 10 gallons is about the max that I have ever gotten in it when I fill up with the light on solid.
 
You can take out the float and adjust as You wish.
I suggest to open it and clean to get better contact. If don’t want to open there are two small windows- where You can adjust when light comes on and fuel level sender. ~20 minutes job.
I adjusted on mine that light comes on when level is 1/3.
And light is also fleshing at 1/3 level, it is steady when less.
 
My experience with my two X’s is that the low fuel light will start flashing when there is still a couple of gallons of gas still in the tank. The flashing is caused by the fuel float bobbing up and down as the fuel sloshes around while driving. Once the level gets really low, the float is low enough that the warning light contact switch is always closed. I have never had a problem with running out of gas when the light is flashing.
It is possible the sensor is going bad but it sounds like it is working correctly. What may be happening is that considering the age of your car, there may be some sediment that has been slowly building up in the tank over the past 47 years. By the time the float gets low enough for the light to come on, there is just a small amount of gas left because of sediment in the bottom of the tank.
I am pretty sure the tank has a 12 gallon capacity if actually empty, but the fuel pickup is not at the bottom of the tank. 10 gallons is about the max that I have ever gotten in it when I fill up with the light on solid.
Thanks, good info. Problem with buying a car from WD’s is they won’t give you a parts list, or detailed list of what was ‘completely’ worked on, so there’s a good chance the fuel tank wasn’t dealt with.
I‘ll ask my local tech how one cleans out a fuel tanks sludge, or at least checks for it - small cameras?
Every car I’ve owned gives you at least 20 miles notice. If it’s possible to raise the floats height, maybe that’s the best solution...
 
You can take out the float and adjust as You wish.
I suggest to open it and clean to get better contact. If don’t want to open there are two small windows- where You can adjust when light comes on and fuel level sender. ~20 minutes job.
I adjusted on mine that light comes on when level is 1/3.
And light is also fleshing at 1/3 level, it is steady when less.
Is this in the Wiki service manual?
 
My Xs have a drain plug at the bottom of the tank. One thing you could do is--next time the low fuel light comes on, go directly home. DO THIS IN A WELL VENTILATED OPEN SPACE OUTSIDE WHERE THERE ARE NO PILOT LIGHTS OR SPARKS. Put the car up on level jack stands and drain the 2 or 3 gallons into collector pans. Measure how much comes out. Then see if there is any rust junk or sludge in the bottom of the tank. With a 2 or 3 inch piece of bent coathanger, probe into the bottom of the tank and see if you have a sludgy build up there. Then decide what tank maintenance you need to do next. The tank comes out the bottom. Replacement of the tank is easy with one caution: The car must be the (tank height dimension) above the ground or you will not be able to get it all the way out.
 
My Xs have a drain plug at the bottom of the tank. One thing you could do is--next time the low fuel light comes on, go directly home. DO THIS IN A WELL VENTILATED OPEN SPACE OUTSIDE WHERE THERE ARE NO PILOT LIGHTS OR SPARKS. Put the car up on level jack stands and drain the 2 or 3 gallons into collector pans. Measure how much comes out. Then see if there is any rust junk or sludge in the bottom of the tank. With a 2 or 3 inch piece of bent coathanger, probe into the bottom of the tank and see if you have a sludgy build up there. Then decide what tank maintenance you need to do next. The tank comes out the bottom. Replacement of the tank is easy with one caution: The car must be the (tank height dimension) above the ground or you will not be able to get it all the way out.
In a proper shop with a proper lift, how long should a mechanic need to swap out a tank?
 
After screwing around trying to clean my tank with it in the car unsuccessfully, I pulled it out. It is actually a pretty easy job. I used OxyClean and it made the inside of the tank look brand new. It is very effective at dissolving sludge and varnish build up and is an all water cleanup.
 
After screwing around trying to clean my tank with it in the car unsuccessfully, I pulled it out. It is actually a pretty easy job. I used OxyClean and it made the inside of the tank look brand new. It is very effective at dissolving sludge and varnish build up and is an all water cleanup.
Good to know. And the float - is that easy to manipulate, test or adjust?
 
The sender/float mechanism is easy to remove out the top of the tank through the large port in the engine compartment. Once out you can look down into the tank with a flash light and see the interior pretty easily.

A new sending unit is pretty inexpensive and they are available.

If taking it to a shop, I would buy a new tank and a new sender, both are available from several vendors. Give them the parts and have them pull the old one then install the new one, having a shop dick around with cleaning an old tank is just not economic. There are a few threads on the replacement which is pretty easy once the car is on a lift, placement of the one lift arm will be important as the tank comes out the bottom of the car right behind the drivers door.
 
The sender/float mechanism is easy to remove out the top of the tank through the large port in the engine compartment. Once out you can look down into the tank with a flash light and see the interior pretty easily.

A new sending unit is pretty inexpensive and they are available.

If taking it to a shop, I would buy a new tank and a new sender, both are available from several vendors. Give them the parts and have them pull the old one then install the new one, having a shop dick around with cleaning an old tank is just not economic. There are a few threads on the replacement which is pretty easy once the car is on a lift, placement of the one lift arm will be important as the tank comes out the bottom of the car right behind the drivers door.
Thanks. After I sort out whether or not the alternator needs replacing (likely), the gas tank will be next on the list.
 
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Last time I took my float out, the float had a pinhole in it and was half filled with gas (which would make the low fuel light come on later than it should). Maybe your float is flooded.
 
Last time I took my float out, the float had a pinhole in it and was half filled with gas (which would make the low fuel light come on later than it should). Maybe your float is flooded.
Thanks - worth a look :) My tank is full - any recommendations on how to safely remove a float without blowing up?
 
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