Donnie2001

2001 vette

gas tank is full and gas gage went to empty while driving.
it has done this one other time, and it fixed it self while
driving.

Jnape

Always buy tier 3 gas. Put a can or two of techron or equal through the tank, one at a time of course. Should clean the sensors off.

Z06ster

This unfortunately is a common problem with C5's. Many on this board will tell you to use a bottle of Techron or SeaFoam in the gas tank. They claim they had success resolving this issue. I didn't have luck with these solutions. The problem is caused by corrosion of the fuel level sensor that part of fuel level sending unit assembly. There are two fuel tanks and either both fuel level sensors go bad or only one. You need to know you can't buy the fuel level sensor by itself. You have to buy the entire fuel sending unit assembly.

Here is a picture of the problem,



The electrical traces on the fuel level sensor get corroded. The traces should be as shiny as a half dollar, but you can see the black corrosion.

Jnape

Very true. The cars that get stored for long periods with less than full tanks of fuel see a lot of moisture. Low quality fuels deposit a lot of sulphur. I got lucky, my '02 Z was doing this at 110,000 miles. I ran Techron through it 2 times and it has yet to return as of 135,000. My '04 vert has never done it in 50,000 miles.

Donnie2001

First thing thanks for the help !!!!
Can I buyTechron or SeaFoam at local auto parts store???

87SAM

Yep.

01_torch_red_vette

+1 on the techron. Mine started to act up on me and techron cleared it right up. My feul level pegged at E a few times and also wouldn't quite read full after filling the tank. 1 bottle of techron and it reads full again and havent seen the level drop since. I plan on running a bottle through it once every month or two from now on.

k0ts

You can change out the fuel transmitter that is in the left tank but the whole assembly has to be replaced in the right tank.. You should be able to learn which side is the problem by the codes you get from the DIC..

I'm having the same problem and mine happens to be the right side.. The GM part is about $366 (left side is about $100)... I understand it's not too bad of a fix.

AU N EGL

try Techone first, then change brand of fuel you use for several tanks

rws.1

Any high quality fuel system cleaner will do. Shell V-power Berryman's Chemtool B 12
Valvoline Synthetic
I prefer Shell V-power

YOu should find one of them also at your local major grocery chain and Walmart.

rws.1

use one of these gasolines
www.toptiergas.com

rws.1

There can be several potential issues

fouled sensor.... fuel system cleaner will clean it
bad ground... find and clean
corroded sensor replace

it can be reached from the rear wheel well.

LoneStarFRC

Incorrect. That applies to passenger side only.

k0ts is correct. The driver's side sender/float assembly (GM part #10333749) IS available separately. Bought mine from a forum vendor for $86.50 + 8.95 shipping.

The right side (pass.) part # is: 89047746 w/improved sensor card (or AC Delco part #MU1218 [for '01-'03]....same thing) This assembly is the siphon-jet pump/float/sender assembly (all-in-one unit).

Either replacement is not that difficult and you do NOT have to drop either tank.

HTH