Thanks guys for all information. But I think the f!?!!?ing fuel sender makes fun of me!!! I just noticed that if I had less fuel in the tank then half the fuel gage would work normally. But it drops like before after some minutes to zero again. I dont understand why the pointer on the gage is going up when I press down the brake pedal. Even when I'm standing still and press down the brake pedal the pointer is going up to right level when I have less then half fuel in the tank. If I have more fuel then half the pointer is going up only to half tank and then it drops to zero again. I know that cod 2067 (on 2004) is fuel sensor right tank low voltage. But I dont understand this with the brake pedal. A guy working with GM cars and Corvettes told me that GM said that I must have new software for the fuel sender. On Monday he is going to help me with the problem. He have this software.Has anyone heard of this with new software????

 

You really should fill out your info.

 

I'm going to do so when i know more about the software

 

I've not heard of any neew software load but the fuel sensor is well known for being flakey

Try using Top Tier gas such as Chevron or Shell. Both have cleaning additives which prevent the build up of sufur which causes this problem. chevron has Techron

Also try a few bottles of Techron through the system ($10 at Autozone). In my case I had a gauge that would build straight to 3/4 and then slowly creep up to full. A few bottles of techron and the snag never reappeared.

 

http://www.corvetteactioncenter.com/...Gauge+Readings
http://www.corvetteactioncenter.com/...Gauge+Readings
http://www.corvetteactioncenter.com/...ram+the+PCM%29
http://www.corvetteactioncenter.com/...ram+the+PCM%29
http://www.corvetteactioncenter.com/...sage+Displayed

I have heard of doing flash programing on modules which sounds like what
they keep referring to as software. You need software for the Tech II to
be up to date in order to do a flash reprogram or recalibrate a module
they are going to do to your sender If there reprogramming does not work
than read the above links

 

There is a GM Tech Bulletin which refers to reprogramming for the fuel gage problem. I'm no expurt but I think all they are doing is compensating for the increased electrical resistance at the sender caused by sender wire corrosion. It is my understanding that sulphur in the gas causes the corrosion and if you catch the problem in the early stages, Chevron Techron and top tier gas will clean the corrosion.

While picking up some parts at the dealer, a guy came in with a sender he was replacing and I could see the sender wires had been completely eaten away. Try the "Techron fix". It's not expensive and certainly won't hurt anything (cleans your injectors at the same time.)

I had the problem about a year or so ago, on a '98. Ran tank down to 1/4, added 20oz bottle, filled tank. During normal use, ran it down to 1/4 tank again and then added a 12oz bottle. Haven't had the problem since. I add a 12oz bottle to about every 5th fill-up. Periodically, it is on sale at Advance, Autozone, etc..

Hopefully this will help you. If sender itself is bad then you are into "phase 2", $$$$$ unless you have warranty.

Cheers.

 

Thanks for these helpful threads. My 98 has these random problems. Do not think Techron helps, have tried - no difference - Shell is my daily gas. Seems like runtime is a factor since on my commute which is 55 mls every morning, the tank goes to empty after about 50 miles (40 minutes) every day..

 

I have used the Techron in my '97 when the fuel gauge problem would come up. Last time I tried the GM Fuel System Treatment and so far it seems to work best..it's been over 3 months and no fuel gauge problem.

 

Maybe it will help if I explain how the fuel system works and how the DTC gets set ....

Basically, there are two tanks in a Corvette, with the left tank being the primary tank and the right tank the secondary. Let's assume you start with both tanks full and drive out of a fuel station. The fuel pump that feeds the engine draws fuel from the left tank. As the fuel leaves the pump, some is fed thru a small line to a siphon pump in the right tank. That pump then passes siphons a greater amount of fuel and feeds it to the left tank thru another hose.

So, as you drive along the IPC expects to see the level reported in the right tank dropping, with the left tank staying full.

If, as you drive, you have covered a certain number of miles or engine run time and the IPC still sees both tanks as "FULL", then it knows the right fuel level sensor is stuck, sets the DTC, and gives you the LOW FUEL and other signs.

There are numerous conditions that can set the DTC (more indicated fuel in right tank than left tank after X minutes of engine run time) ... the "new" software changes some of the "calibrations" for setting the DTC (it makes the car less sensitive) but if you have a sticking right sender, the software won't "fix" the problem.

No idea why stepping on the brake pedal affects the fuel gauge as there is no common wiring .... tho I haven't looked in the manuals for ground points .... JUST POSSIBLY the brake lights are overcoming a "ground" issue for the right fuel sensor when the lights are on.

 

Guess what, the right rear fuel level sensor and the brake lamps share the same ground point G401.

It is located on the inside of the frame rail, Left side of vehicle, and about opposite the rear wheels. The transmission harness grounds there too.

I'd check that ground point for corrosion, and the wires attached to it. Clean it up and put it all back together ... there is a REMOTE chance that a bad ground is causing this.

Good luck,