Question for camaro tank users

[clemsonteg]

I installed a camaro tank in the rear, but I'm only getting about 14 gallons into the tank when I fill up. I think it's suppose to be an 18 gallon tank. What is everyone else seeing in the way of capacity?

[57larry]

I also thought it was 18 gallons

bump

[clemsonteg]

Filled up with gas today and I carefully added fuel until it started to come out of the fill neck and I got nearly 12 gallons. My gauge was reading between 1/8 and 1/4 tank before the fill. Once full, the gauge reads exactly on the full mark. I noticed that if I unplug the sending wire from fuse panel that the the gauge goes way past full. I am guessing that the new sending unit and the old gauge plus an extra 10 feet of wire to reach the sending unit is causing the gauge to read lower than it really is. I could probably pull the sending unit out and make some adjustments, but it won't be today.

I suppose the real test would be to drive until it runs out of gas and then fill it up, but I don't think the wife would like me and the boy being stranded.

[clemsonteg]

Filled up again yesterday and only managed to get 13 gallons. Gauge was on E and I didn't want to overfill the tank so I stopped when the automatic shutoff from the pump kicked in

[frankslagoon]

sounds like the sending unit is goin to mt before the tank is. only one way to find out. make sure ya got 5 gals in the trunk

[67ChevyRedneck]

I've never used one, but it could be the sending unit doesn't mesh with the truck gauge?

You can tweak your gauge if you want to.

For my truck, when "full" it always read almost 1/4 tank past "F", then when it was on E, I had about 5 miles left, so it could be gauge. When I redid my gauges, I pulled the needle off the fuel gauge, pulled the sending unit out of the tank, grounded it, turned the key on, then let it drop to empty, reinstalled the needle 1/8 tank below "E" so now it should read about 1/8 below E when completely empty and it's a hair above 1/8 past F when full. Little bit of a pain, but I like having a few gallons left when on E. Just make sure you're happy with the needle movements before putting everything back together.

If you really want to check the tank, do as above and drive until you run out. I almost ran out in my Z71 once in the middle of nowhere in PA. I could not find a damn gas station. I finally found one and I put 26.1 gallons in my truck (26 gallon tank + what filler neck would hold. I was literally a minute or two from walking. Ran out of gas a few times over the years, but this was the "closest" I ever came to not running out, but almost.

[clemsonteg]

Thanks for the advice. For reference, the tank and sending unit were purchased new in August. Doesn't mean I don't have a defective part, but I thought I would add that tidbit.

I have included 3 photos below with the various positions of the gauge. With the sending unit connected, with the sending unit disconnected and with the gauge grounded.

It seems like if I were to do any tweaking it would be in the same direction as 67chevy, which I think would confirm my suspicion that the tank is not filling up all the way, correct? I hate to drive it until it runs out of gas, but I may have no other option if I want to find out the true capacity of the tank.

[clemsonteg]

I forgot to add that the photo of the sending unit connected is the position after I filled the tank and drive approximately 20 miles. When I filled the tank, the needle sat pretty close to the last hash mark which I assume indicates full

[Mapearso]

Mine just went in this weekend. I know its supposed to be ~ 19 gallons

I'll let you guys know what happens when I run it down and try to fill it!

[71meangreenc10]

Have you checked the sending unit for Ohms when it is empty and full? Your second pic is normal to me as mine does the same thing. If I am correct it should be 0 ohms empty and 90 ohms full (or the other way around). I think your issues are in the sending unit.

Smitty

[clemsonteg]

With the 7/8 of a tank currently showing on the gauge I am seeing 87 ohms. At 0 ohms (gauge grounded) it goes to the empty level in the photo above. The only item I could see that would possibly need adjustment would be the float on the sending unit.

I also did some searching on some Camaro forums and found that they have experienced similar issues and they attribute it to the filler neck protruding too far into the tank causing an air block. I can't tell by looking into the tank if that is the issue for me.

[clemsonteg]

I did some searching and I couldn't find a definite answer, are the full swing marks correct with it grounded and disconnected?

[71meangreenc10]

Originally Posted by clemsonteg

I did some searching and I couldn't find a definite answer, are the full swing marks correct with it grounded and disconnected?

In my opinion yes.

Smitty

[clemsonteg]

Originally Posted by 71meangreenc10

In my opinion yes.

Smitty

Thanks, Smitty. That's sort of what I figured. I think I am basically down to either an improperly set float in the tank which needs adjustment to accurately represent the fuel level of the tank, or a massive air pocket caused by a poor reproduction and the filler neck protruding too far into the tank. I suppose the only way to know for sure is to either drop the tank to check the actual fill amount and sending unit range, or run the tank dry with a back up can in the back.

The tank is actually limiting my ability to go lower on my bags, so an upgrade is needed, but I would like to find the root cause of my issue for future users and so I know if I can make a move to a 70 chevelle tank and keep my behind the plate fill or if I need to upgrade to a Boyd Welding tank and relocate the filler neck to the bed.

[clemsonteg]

I tried to run the truck out of gas this weekend and I couldn't bring myself to do it. I drove about 40 miles after the needle hit Empty and stopped moving. I did the stick in the tank test and figured I had less than a gallon left in the tank. My fill up this morning was 16.8 gallons which is way more than previous fill ups. That puts me pretty close to the range specified by the manufacturer. I think I could probably take the sending unit out and tweak it some to better represent the gas in the tank, but now that I know my limitations and that the tank actually holds what it is supposed to, its not really much of a concern.