Any way to know how much fuel in tank?

[e30Matt]

The late model gauge in an early chassis will read double what's in the tank, because it's designed to use both senders (which are variable resistors) in series instead of a single, thus dropping the voltage returned to a much lower value. When it sees a much higher signal from the sender (due to there being only one), it reacts accordingly and reads higher because it's calibrated for a lower signal.

The early model gauge works exactly the opposite, reading full at a full tank, but empty at only half a tank in a late model, due to the lower voltage return signal.

The gauges are not interchangeable between chassis, but they are interchangeable between brands (VDO/MotoMeter).

[Jand3rson]

Well, I'll get on that! I still need to find a super-eta tach. Anyone got one?

And all this just because I wanted my tach to read 6k instead of 5k. I just wanted to see my real redline. IS THAT TOO MUCH TO ASK???

[Jean]

Really? I have never heard of that! Can anyone else verify this? So when I fill it up, it should be normal all the way until it gets to dead empty, and will then go back to 1/2 and the light comes on? And a seta is an '88, so that would be considered a late-model (facelift tails and wheel arches).

When I first put it in, it was reading just a little over 1/2 a tank. So I've driven it a few times since then, and now it's dead on 1/2, and the light is on.

That is correct! Whenever I install a late model cluster in my early car, the fuel gauge reads wrong...you have to rememember that the low fuel level light is a on/off switch, so it doesn't matter if the gauge reads right or wrong...the on/off is right.

I have a late model cluster in my car, and the fuel gauge itself is from my original / early cluster and everything works as it should.

So, I would swap the knowing good fuel gauge from your previous cluster and it should be fine.

[E30SPDFRK]

Not sure. I got pissed off with it quickly and changed it. Now it works like normal.

[Jand3rson]

I can tell you that when I put a 89 cluster in my 86 it happened to me.

Did it really normally until it got to that point?

[ak-]

Suckers. $2.73 for 91 here. :D

lol, that's still more then our 87 octane.

[StereoInstaller1]

Yeah, late gauge reads bad in early cluster too.

[E30SPDFRK]

I can tell you that when I put a 89 cluster in my 86 it happened to me.

Give it a try, should only take like 10 minutes to swap that one gauge.

[Jand3rson]

The fuel gauges from late models installed in early models read half tank when they're empty. Not sure if the seta is considered a late model or not, but its worth a look. The gauges are interchangeable.

Really? I have never heard of that! Can anyone else verify this? So when I fill it up, it should be normal all the way until it gets to dead empty, and will then go back to 1/2 and the light comes on? And a seta is an '88, so that would be considered a late-model (facelift tails and wheel arches).

When I first put it in, it was reading just a little over 1/2 a tank. So I've driven it a few times since then, and now it's dead on 1/2, and the light is on.

[Philo]

Suckers. $2.73 for 91 here. :D

[ak-]

Fill her up.
It's like $3.25 for 90+ octane here :puppy:

[E30SPDFRK]

The fuel gauges from late models installed in early models read half tank when they're empty. Not sure if the seta is considered a late model or not, but its worth a look. The gauges are interchangeable.

[Philo]

I guess so. I still need to shell out for the little gear to make the odo work, but i'm too much of a cheap ass.

[Jand3rson]

I might need to swap out the tach as well, it's been having issues. I suppose I could swap the fuel gauge out of my eta cluster, they're the same. That's why I'm thinking I might as well just get another cluster.

[Philo]

You should be able to just swap out the fuel gauge if I remember correctly. It's been awhile since i've had mine apart.