[PaulS]

My fuel gauge isn't going down like it used to.....not necessarily a bad thing but I want to understand the dual tanks so I can figure this out.

Gauge is at full mark but yesterday I made several in town trips so I'm wondering if something is up. I go to the gas station and am able to add only 4.8 gallons but I'm thinking if the tank needed 4.8 gallons shouldn't it have been lower than full? Now the gauge is reading just over full.

Is this what's going on with my tanks:
The secondary tank is full but is no longer sending fuel to the primary tank therefore it's a matter of time before the primary tank runs out and I'm stranded...

Any recommendations on what to check? Is my thought process correct?

p.s. I had the gauge going to empty problem last year, many many times. I just reset the code and didn't worry about it. In January my battery died and since replacing the battery, I haven't had the problem with the gauge going to empty. I've put about 3K miles on the car since the battery change.

 

[Melsy]

Did you take your car to the dealer last year when you had the guage problems? I have had mine into the dealer 7 times for guage problems and GM even sent me a letter extending my warranty for those problem(s). Welcomd to the world of GM fuel guages. Recommend you talk to your dealer and cite the universal problems you've heard about that problem. Are you still in warranty? :-?

 

[IT L GO]

Do a Search on fuel guage problems. Fuel cleaners seem to help. :z:

 

[yankee0304]

I don't have all the service info in front of me, so I may be wrong in some of my info. My understanding is that the fuel level sensor is in the secondary tank. That should be inline with the transfer pump. I don't know if they are on the same circuit or not. However, the normal spec is between 0-90 ohms on the fuel level sensor gauge wiring. I don't remember which resistance number matches full and empty and I don't know how to test it on a 'Vette. I wish I could be of more assistance.

 

[PaulS]

Thanks Yankee.....

I think I may just be a bit paranoid and will drive close to home for a while until I get some miles on it. I just don't remember the needle staying at full for so long....I thought it pretty much started working its' way down after about 30 miles!

There's a large pipe between the two tanks which lets them level out so I don't think it is possible to have one side full and the other empty. Otherwise, you would only be able to fill your tank 1/2 full at the pump with your engine off...

There is a long post on how the fuel tanks work and how the sensors in each tank work (doing a search on fuel tank). Unfortunately the post refers to each tank as left and right....I've never figured out which part of a car is left and which is right, lol.

Maybe someone will read this and respond with how things work...I'm just guessing, based on what's happening.

 

[spdrcrj]

More than likely, you need one or both of your fuel sending units replaced. I've had my left one replaced 4 times and the right one once. Using chevron fuel seems to be keeping things clean since the last swap. Also, go into your DIC and see if you have any codes. If you have one for fuel quantity, clear it out and your gauge might come back, it worked for me.

Jim