Whats the 99 fuel tank size 19 or 18 gallons? I had put two bottles of techron 12 oz fuel system cleaner concentrate in and 12 gallons in addition to what was already in the tank read about a 1/4 but cant trust it as much once you've ran the passenger tank out and only put gas in the drivers side 20$ or so when needed.

Im using the techron fuel system cleaner concentrate to clean all deposits off the sending unit as well as trying to make sure the second tank gets atleast 3/4 full.
Once running the 99 fuel pump on the drivers side cycles from both sides evenly until empty or low on the passenger then just the drivers side?

So is it safe to say with 12 gallons and 3-5 gallons the tank is near full? The gauge is now reading full but as i seen when working properly goes to a low reserve on the cluster which is a couple gallons or enough to get to the gas station home or wherever.

Thanks guys.

 

Owner manual says 18.5, so you are "near" full.

 

Thanks so there is a sending unit on each side which sends a certain amount of ohms from each to determine fuel level? I see it has a one way check valve on the passenger tank to pick up fuel from that tank as well as drivers side while operating so it uses fuel from both tanks while driving or operating and not just one then the other? May i ask is the fuel pulled evenly from both sides or does it vary a bunch and just a design in the gm fuel system to run 1/4-3/4 tank though having the low reserve is nice.

The 00 tanks are the same as a 99 97-00 my 99 uses a single fuel line to the fuel rail and metal tanks. What year did they switch from two lines at the rail to one line and from metal tank to plastic? This is for another car trying to put together. My friend has a 02 missing fuel tanks, pcm, harness, has bcm and dash HUD.
Im trying to see if its possible to just swap the complete plastic fuel tank and lines from a 00 model to a 02 model that still has the lines up to rail but no fuel tanks. They were used on a factory gtm 5 supercar. Are all HUD dashes the same 00-02 and interchangeable? The 00 6 speed convertible parts car is just missing the key, engine and seating. The 02 clean title base car is nearly stripped except for paneling, doors, glass and am going to try to swap the whole 00 convertible harness unless its easier to wire what was an 02 auto 70k mile car that was cut right at the tac and pcm and splice in the 6 speed pcm or different wiring as well and is it possible to completely swap the 00 convertible electrical harness to the 02 base car as well as fuel lines. I understand all driveline parts interchange, etc.

 

Tank size on the C5 is 18.5 gallons, so if your measurements are good, you are near full as far as the gas tanks go.

 

Great thanks yes i only added 1.6 gallons this morning before the pump cut off. Thanks im going to try and only fill it 15-16 gallons so the gas isnt up at the top. How durable is the rubber crossover tube they use to join the 99 tanks together, how long do they last and are they easy to change or anyone had failures the car is 24 years old im not sure how long that rubber will last. I hate to keep gas maybe possibly in the rubber crossover tube which is what i seen from under the car.

I see the 00+ plastic tanks dont have a rubber hose but this metal crossover hose if anyone can answer the question? Seems harder to change the pump but the hose looks to be metal and not rubber?

This is a 03-04 or 00+tank metal crossover hose and what i think i saw was just a plain old rubber hose joining the 99 tanks together, correct?

Sometimes i question as i just bought the car may 2021 i forgot i was tied up since late 2012 how old these cars are how long the plastic or rubber lines may last. In the regular weather in the garage i expect them to last forever.

They're would be an evap code if there were fumes or something leaking from the evap canister or other tank fume equipment?
Just looking may have to put a 00 tank setup in an 02 that was missing tanks. Are the 00-02 tanks the same or 00 still is a metal tank/plastic? or direct fit with lines on the 02 body style?

When normally running or engine on it pulls fuel from both tanks simultaneously? About the same amount so the tank drop evens out or from one side only then the other or how does this operate? Im trying to keep it so the low reserve display still shows when low on gas and not the trouble starting it when it reads 1/8-1/4 one morning i had tank get a gallon in a small tank and the car started right up.

 

sorry are they all plastic just different design for the fuel pump access i may have confused it with the 98 z28 metal tank vs 99+ z28 plastic tanks.

 

Yep. 😏