t2d2

iTrader: (8)

I just filled up the '98 for the first time, and it took only 16.1 ga despite the needle just hitting the 'E' mark. Most cars have 1-2 ga left on 'E', but mine would have 4-5 ga left.

It could be coincidental, but that's almost exactly how much my '94 has left in the tank when it's on 'E'. (Which led to a nasty surprise when changing the fuel filter shortly after buying the car, thinking the tank was almost dry, and having 5 ga of gas running down my arm and torso while struggling with the infamous SC fuel lines. Blistered skin for weeks.) Are all SCs like that? It's better to read low than to read high, but an accurate reading would be even better...

oldManTan

when my SC was low on gas i would keep driving a few miles with it over the letter E, it was the lowest the needle could go but even then i would put 17.9 gallons in. so yea, the light comes on pretty early.

t2d2

iTrader: (8)

I've never actually gotten the light to come on, since I don't like pushing my luck when it's on 'E'. It would be just my luck that the one time I tried, the gauge would recalibrate itself and I really would be on empty...

​Seems pretty pointless to have a gauge that doesn't read accurately, if it's by design. Just have a high/medium/low dummy warning system.

RXRodger

iTrader: (2)

There are a couple of things at work here I have found out since I started racing my black SC. You can not get the last gallon or so in due to the way the tank vents without squeezing it very very slowly. It has to do with the way the neck enters the side of the tank. Pull the trunk interior lining back you will see what I mean. I had to tap a 1/2" hole in the top vent flange and put a large vent (routed to the left, then up, then out the right side fender behind the tire) to be able to dump fuel quickly and use all of the capacity. Then, as you have noted, when you hit E you aren't really empty, I estimate around 4 gal left. If you run to when the light stays on steady, you don't have a lot left. I have actually dumped a little over 20 gal after that happens. The good thing is you get some warning, when you make a hard left hander on track it sputters and when it does you better come in. I have yet to run the car all the way out, but that is as close as I have gotten it. So, to get the last amount in to get it full, you gotta go slow or vent larger. To get all of the capacity at the bottom, you have to run it until the light is on steady.

t2d2

iTrader: (8)

I know all too well what you mean, having pulled a couple fuel tanks in diagnosing start-up problems. I see your point, but I assumed that would have been factored into the ~21 ga capacity.

It's sounding like that is indeed by design then. Note to people changing fuel filters: Run the tank way past "E" and/or siphon it first!

So, the low fuel light flickers on and off before being lit steady, with the final stage being the true indicator of low fuel? Or is that only in hard cornering?

KahnBB6

iTrader: (5)

All I know is that when I first bought my car I had to replace both the fuel tank level sender AND the fuel gauge in the cluster with new parts. It was actually my cluster gauge that was not reading correctly after it reached the halfway mark. It's possible that before I bought it that gauge had exhibited more minor signs of inaccuracy before it got that bad. The tank sending unit did also help but in my case it was both but it is possible that these analog fuel gauges do not remain fully accurate over time. However I do believe they can be recalibrated or rebuilt.

RXRodger, your post is very enlightening. These cars have huge fuel tanks and I am not surprised that once the low fuel warning light comes on it is far from close to being empty. That said I try to never chance it in mine.

t2d2

iTrader: (8)

Maybe Tanin could weigh in on whether that's part of, or an option with, their gauge cluster service? Also, to the original owners among the forum members, did your fuel gauge always read low or did it gradually shift to that behavior, if at all?

RXRodger

iTrader: (2)

I already talked to them about the issue. I asked do they do a full range calibration, they said they do not, they only repair them to the range they know they operate at. At least that is what I remember, maybe they will see this and weigh in.

t2d2

iTrader: (8)

^ That sort of sounds like acknowledgement that they read low by design and there's not much point trying to do anything about it.

Chattanoah

Quirky for sure, I've personally never brought it that low, but I have accidentally waited to fill up at almost empty and I recall it not being quite as much I expected. Among other oddities, the gauge goes up suuuuuper slow, and then there's that unbelievable woosh of vapor release when unscrewing the cap. Maybe SC's are just born with it. They are pretty odd cars, so...

RXRodger

iTrader: (2)

If you are getting pressurization, you probably have a plugged up carbon filter or pinched vent line. My red SC has this issue, I just haven't taken time to do anything about it. Like I said earlier, I solved it on my black SC by installing a 1/2" vent line, but it is only for race duty and so I can dump 5 gal containers in it in about 20 seconds.