G50 - Low fuel warning light - how many gallons should be left?

[tkd_q45]

Wasn't sure if I should post this in the Mechanic section but did not seem "important" enough -

Anyhow - the other day I drove until my low fuel warning light came on. Now on our 96 I can drive for over 40 miles w/o running out. On my 94 I was running out after 15 miles - actually out where my car was stumbling due to no gas. I went to the nearby gas stationg where I had to buy a one gallon container. Well filled that one gallon and my low fuel light went off. Seems a bit unnerving that my low fue light would not come one unitl I only have one gallon left. Any insights?

[AZhitman]

One way to tell:

Drive until low fuel light comes on, fill tank, and subtract amout added from capacity.

[Q45tech]

In theory when the car was made the separate sensor that drives the light was adjusted to energize with 2.5 gallons left in tank.

Still I would expect a 5% or +- 0.125 gallon accuracy.

How many miles per gallon is the variable that depends on fuel composition, temperature, and rpm.

Somewhere between 25 and 60 miles if all the fuel can be utilized.

Not refilling when at least 1/4 is a primary reason fuel pumps fail EARLY from repeated overheating.

[tkd_q45]

Did not know about the 1/4 tank fuel pump burn out situation. I will do this from now on. It is rare for me to drive until the fuel light comes on.

[Rex]

I usualy fill up just as I reach 1/2 tank. The additional fuel in the tank acts as a coolant "around" the bump, allowing it to operate more efficiently, drawing less "power" through the FPCM.

[xmateo]

the light on my Y33 is out completely. didn't know how much I really relied on the dummy light. Is there an ez fix for this?

[ceningolmo]

the light on my Y33 is out completely. didn't know how much I really relied on the dummy light. Is there an ez fix for this?

Follow Rex's advice and just fill up at 1/2 tank...you'll visit the station more often, but you won't run out of gas on the side of the road EVER. Probably worth the extra time it takes to fill up more often.

[ceningolmo]

In theory when the car was made the separate sensor that drives the light was adjusted to energize with 2.5 gallons left in tank.

Still I would expect a 5% or +- 0.125 gallon accuracy.

How many miles per gallon is the variable that depends on fuel composition, temperature, and rpm.

Somewhere between 25 and 60 miles if all the fuel can be utilized.

Not refilling when at least 1/4 is a primary reason fuel pumps fail EARLY from repeated overheating.

And... if you have burned up a fuel pump in the past, and replaced the pump yourself, there is the possibility that you bent the float mechanism that shows how much fuel is in the tank. Its a bit of a tricky maneuver getting the fuel pump and float through that little hole on top of the tank... bend, twist, pull, or push too much in the wrong direction and you may have modified your fuel gauge accuracy.

Add this possibility to the listed variance of accuracy by Q45tech and you might begin to wonder whether you are even safe at 1/4 tank?!? Best bet would be to follow AZhitmans original advice. Drive until you are at 1/4 tank (or low fuel light comes on), then fill the tank. Subract that from the tank capacity and you know how much is left at 1/4 (or when light comes on).

I can testify to this one myself.

[xmateo]

Follow Rex's advice and just fill up at 1/2 tank...you'll visit the station more often, but you won't run out of gas on the side of the road EVER. Probably worth the extra time it takes to fill up more often.

thats not really relevant to my question. thx tho

[Q45tech]

Totally empty your tank them wipe it clean, then refill slowly a ML at a time until the warning goes off..............unfortintely errors will creep in because the car body/tank can be affected by inclines, road undulations, accelerations and decels.

Create your own gasoline gauge via this method read the voltage on an accurate digital VOM and translate to ounces remaining.

Be sure to precisely regulate the voltage to sensor and calibrate for gasoline temperature [the resistance of the potentiometer will change with temperature].

How much is in strainer, pump, lines, filter, rails, and return lines?

Honey we only have 2560.25 ounces of gas left. [128= 1 Us gallon]

[MinisterofDOOM]

And... if you have burned up a fuel pump in the past, and replaced the pump yourself, there is the possibility that you bent the float mechanism that shows how much fuel is in the tank. Its a bit of a tricky maneuver getting the fuel pump and float through that little hole on top of the tank... bend, twist, pull, or push too much in the wrong direction and you may have modified your fuel gauge accuracy.

I ran into an additional issue when I replaced my fuel pump: the little filter on the inlet has a fringe around it that just BARELY hits the float on it's way down. It doesn't appear to interfere with the gauge accuracy, though. It must hit the float at a point below dead empty.

unfortintely errors will creep in because the car body/tank can be affected by inclines, road undulations, accelerations and decels.

My old Coupe Deville was so susceptible to inclines that the needle would lean against the car. If you were on an incline leaning to the right, the needle would compensate by leaning left. So if the tank was half full, the needle would always be pointing straight up, no matter which way the car was leaning.

[CrimsonQ]

My old Coupe Deville was so susceptible to inclines that the needle would lean against the car. If you were on an incline leaning to the right, the needle would compensate by leaning left. So if the tank was half full, the needle would always be pointing straight up, no matter which way the car was leaning.

Lol thats sounds just like the wifes 93 Park avenue.

I think my gauge is off as well. Not really an issue though as i never drive far.

Or maybe theres some dope or money stashed in it