Fuel capacity wrong

When I let my gas run down until I get low fuel warnings on the dic and on the gauge, it only will take about 13 gallons until it is filled. I can actually hear it coming up the tube so I know its not a false full. Everything seems to working perfectly as far as the dic is concerned, just that all the mileage adds up to me having a 14 gallon tank. Is there a way to reset the real empty or do I have to replace parts?

Thanks all
GoBears

Was the fuel pump assembly or fuel level sending unit ever replaced. It sounds like the fuel level sending unit is out of calibration which probably explains the discrepancy.

Also, when the low fuel level first comes on you will have a few gallons left in there.

The gas tank capacity for 2000 models is 17 gallons.

I have no idea if anything was replaced I just bought it 2 weeks ago. Is this something I can fix cheaply or should I just deal with it? Thanks for the quick reply man.

By the way, that timeslip is pretty impressive. What mods u got?

GoBears

There is a check you can perform with a digital mulitmeter (DMM) where you check the resistance specs of the level sending unit at low, medium and high points of the float. If off then you bent the float arm to adjust it in. But before getting to that I recall I have around 2-3 gallons of gas left when the low fuel indication first comes on. This is normal for reserve fuel.

The mods are listed at Dragtimes (http://www.dragtimes.com/Pontiac-Grand-Prix-Timeslip-6428.html).

My GP is the same way. 12 gals DIC chimes, 13 gals low fuel light comes on. The most I ever filled up with was 15 gals.

My GP is the same way. 12 gals DIC chimes, 13 gals low fuel light comes on. The most I ever filled up with was 15 gals.

That's exactly what mine does too. My biggest fill up so far... 13 gallons and that was gurgling coming up the fill tube heh. It's averaging 23 mpg every tankful so I'm pretty happy with that.

GoBears