fuel gauge not accurate

[snira]

Hello,
Everytime that the nidle of the fuel gauge is getting closer to the orange zone it's taking very short time untill it's going under it, it's not going down progressively, it's just fall right down under the orange and stay there, And even if i drive more miles on it, there is more and more to drive.
this is not happening when the tank has fuel above the orange zone.
Because of this problem I can't really know how much fuel really left in the tank and when is it going to run out of fuel.
What part is not functioning right?
thanks

[MattStrike]

Well, short answer is next time it touches the orange zone is to top off the tank. Then subtract the tank capacity from the owners manual (18 gallons) from what you put in. Then you know how much is left when you first reach the orange zone. Every car is slightly different.

[Bob Dillon]

It's not the gauge, it's the shape of the tank. It's L-shaped with the bottom leg of the "L" facing towards the front of the car. This makes the gauge wackier than a traditionally-shaped tank.

[snira]

thanks,
so you guys think that the reason is just because the shape of the tank, and that when the fuel is going down in the tank the gauge will be less accurate, so from my understanding replacing the fuel level sensor will not change anything, right?

[Bugsi]

Believe it or not, there's a factory service bulletin to reprogram the PCM to give a more consistently progressing decrease reading for the fuel level. If you find yourself at a GM dealer, have them look it up and patch your PCM. I don't have the bulletin number, but I know there is one. Whether it actually fixes your problem is another thing, but worth trying.

[1oldman]

I've been around "tired iron" all my life. In-accurate fuel gauges are typical of all the all cars/trucks I've ever been around. - BC

[Bob Dillon]

I've been around "tired iron" all my life. In-accurate fuel gauges are typical of all the all cars/trucks I've ever been around. - BC

Yup. My tagline toy has an inaccurate gauge, I just put $20 in every time I drive it around the block.

[reb]

TSB:

FUEL SYSTEM, GASOLINE:STORAGE:TANK ASSEMBLY

Date Reported DECEMBER 01 1997
NHTSA Reference #600209
TSB Reference #738325

Description: CUSTOMERS MAY COMPLAIN THAT THE FUEL GAUGE REMAINS ON "FULL" TOO LONG. *TT

Repair Information for NHTSA #600209

[renchjeep]

Just a word (or several!) of advice--the electric fuel pump inside your fuel tank is cooled by the surrounding fuel. Running below 1/4 tank consistantly can cause the pump to overheat, and cause fuel pump failure. Plus, by running the tank lower than 1/4, you stand the chance of sucking dirt and debris from the bottom of the fuel tank, which can prematurely clog the fuel filter. This can also lead to fuel pump failure due to overworking the pump.

Fill 'er up at 1/4 tank. It doesn't cost as much per fill-up, and just may save your fuel pump. Also, change the fuel filter every 20k. Cheap insurance...

[1oldman]

Just a word (or several!) of advice--the electric fuel pump inside your fuel tank is cooled by the surrounding fuel. Running below 1/4 tank consistantly can cause the pump to overheat, and cause fuel pump failure. Plus, by running the tank lower than 1/4, you stand the chance of sucking dirt and debris from the bottom of the fuel tank, which can prematurely clog the fuel filter. This can also lead to fuel pump failure due to overworking the pump.

Fill 'er up at 1/4 tank. It doesn't cost as much per fill-up, and just may save your fuel pump. Also, change the fuel filter every 20k. Cheap insurance...

X2

I mark on my filter with a sharpie the date and mileage installed in case I forget (ha ha ha - I always forget!) - BC

[renchjeep]

1oldman--I do exactly the same on all of my vehicles, and the Police fleet that I take care of. It never hurts to have a reminder...and as I get older, I seem to need more reminders for the "simple" stuff!

Now if I could just remember where I put my keys.....and my glasses.....

Seriously, marking your fuel filter with mileage/date will help you, and any other future "mechanics" or owners, to get a grip on possible maintenance (or lack thereof) issues.