Gas Gauge 55 vs 60L

[caffeinatedsoap]

Hey folks. I'm having the most amount of fun with my gas gauge. Maybe someone can help me out.

I have a 92 318ic with I assume the 62(I've heard 63l as well) tank as it has two fuel level senders. The gauge I have in the car is according to realoem a 55L fuel gauge part #62131374822
I bought a gauge with the part #1381 866 on it which I assumed was 62131381886. They both exhibit the same symptom though.

When the tank is full they report full.
When the tank is half empty they report empty.
If I unplug one of fuel level senders the gauge reports empty.

I've verified the tank is half empty when the gauges report empty as I am only able to get ~5 gallons of gas in the car. This seems accurate with the statement on e30 wiki:

The E30 was fitted with two different fuel tanks, a 55 litre and 62 litre. Depending on which tank the car has, a specific fuel gauge is installed in the cluster, which are not interchangeable. A 62 litre gauge connected to a 55 litre tank will still read half when the tank is empty, while a 55 litre gauge connected to a 62 litre tank will read empty when the tank is still half full.

What are other things I could look at to troubleshoot this?
Do I have the wrong gauge?
Could this be a code plug issue? (if so whats your code plug 91-92 318ic folks?)
Could this be some type of mystery wiring issue?


Please Help, this is driving me nuts!

[TobyB]

The senders, if I recall, are 60 ohms each, early or late.

The early car has one, and the early gauge sees 60 as empty.

The late car has two in series, and the later gauge sees 120 as empty.

So it SOUNDS like you have another early gauge. If you have a meter,
you can pull the senders and meter them empty and full,
and if you have a variable resistor, you can make up a quick
test circuit to see what the gauge does.

If you don't have a meter, you can simply jumper across one sender,
and see what happens. (2 spade connectors on a piece of wire)
If you jumper the driver's side, you should see it
drop evenly to half, stay there a while, then eventually plummet to empty
as the car uses up the last 1/4 tank.
If you jumper the passenger side, it should drop evenly to half,
then plummet to show empty as the car empties the driver's side well.
If you take a hard right- hander, it should jump back up as fuel sloshes over.

If it behaves as above, then everything's working right, and you simply still have
an early gauge.

hth

t

[Gregs///M]

Look up your VIN at realoem.com and look up what fuel tank was equipped for your car. Then install the appropriate gauge.

[TobyB]

You don't even have to go that far- just pull the bottom of the rear seat,
and if you have 2 access panels, you have the late setup.

If you want to make sure your tank hasn't been swapped, open
the panels, and there should be your senders.

t