Fuel gage/warning light question
 

I have an 86.5 928 in good condition.
I find that when the fuel gage gets all the way to the bottom of the range, that the warning light has not yet come on, and that the car will only take 17-18 gallons at that point.

The owners manual mentions a fuel level warning light, but does not show where it would be in the gage cluster.

Is there a warning light, and if so where would it be. Aparrently I have not run the fuel level low enough to make it come on yet, because the tank is supposed to hold 23 gallons.

Is this normal, or do I have a fuel gage or fuel level sending unit issue?

Turn your key switch on and check all the dash warning lights....one should be at the low end of the fuel gauge. and yes they are 23 gallon tanks

If you don't have a manual, go here and get one.

Attachment 677211

doesnt show the fuel light though.
Also, whats with the fuel gage being all the way at the bottom with 5 gallons still in the tank. Is that normal.

The low fuel light is the lowest hash mark on the guage, at the R - it should light up orange/red during the bulb check (key on before starting), and when the tank gets to approx 2 gal left. See if it lights up during bulb check.

if the tank is full and the needle is not all the way to the top then it's the gauge, mine is like that and i think a lot of them are like that too, you can fix it i think when you take the cluster apart if you happen to change the odo gear or bulbs etc...

The sending unit is a float on a wire as it moves the resistance changes and the gauge reads the variance and moves the needle. The empty reading is a on of contact which should indacte when about two gallons remain. The sending units are more often the problem than the gauge far more often. Some have cleaned up the wires with success most simply replace the sending unit.

Very late models allow you to calibrate the digital dash cars readings to be more accurate.....info in the manuals

The sending unit varnishes up and the float gets stuck, removing the sending unit and clean up with brake cleaner works perfectly. I used a small toothbrush, but be very careful with the thin wires that hold the float. Replace the seal at the same time.

OK, I do have a light and it works.
Guess I'll run the tank down until the light comes on, and hope that I dont run out of gas first.
Will clean the sender.
Thanks

I would take the sender out and inspect it.. Likely you have rust and varnish build up that would cause a out of range resistance value ..

You can try to fix it with chemicals (chem-dip and gum cutter)..

Also do a search here someone actually reconstructed the float/sending unit, however you can find very good condition units from the vendors here or Ebay for ~ 45-50 bucks.

I had a simmilar problem where the gaige would never go past 2/3 and would not show when it was empty. The problem was the ground wire attached to the top of the sending unit. It was corroded. Cleaned it up and has been fine for over half a decade.

Yes it works by measuring resistance and any poor corroded connection is resistance......

I seem I have a faulty sending unit as the fuel gauge gets down to empty whilst I have not got the R indicator lighting up. I read on the previous posts that cleaning the sending unit is often sufficient to restore it. Can you point me to a detailed procedure to dismantle and inspect the sending unit?

I cleaned my sending unit but there really wasnt much more than some dust there. When I fill my tank the needle lines up with the top line on the fuel guage. But when the needle is all the way down on the bottom line of the guage, and the fuel light is not on. I still have 6-7 gallons in the tank.

Seems that my fuel guage is the problem.
Should the needle go above the top line on the guage when the tank is full, on a good guage?