fuel tanks with 2 level senders

[Gunni]

the car in question had such a tank and now the replaced tank only has the one, lika most others, but the gauge is off,

I have been thinking about this and itԚ´s apparent that the 2 level senders worked together to make a single circuit into the instruments,

remove one sender and short itԚ´s connector and you only get half the measurements, i.e at empty it still shows 30, and at 30 it shows 60,

does anybody have any info on this?
This is the only E30 I have seen with two level senders

[Gunni]

It seems the tank is from 1/90 and later and has a diffrent sending unit,
IԚ´ll have to see if I canԚ´t find another one like ,

[smithy318i]

The two sender tank has a higher fuel capacity and different pipework design.

The two are interchangable, but need a little messing about to get to work properly.

If your going to use a single sender tank, you will also need to replace the fuel guage in the instrument cluster.

[Martinaston]

One sender is a 55 Ltr tank and two is a 63 Ltr.

[Bailey]

Mines got a two sender tank, and to my knowledge the small sender opperates the low fuel warning light. whereas i think that the larger sender opperates the level indicator

[DaveD]

thats what I found when I changed mine

[DanThe]

Listen to smithy

He and I have encountered this before, if you change the amount of level senders then you also need to change the gauge.

[Gunni]

I already changed the gauge to the one from the previous car,,,,

IԚ´ll see what happens and let you guys know

[Gunni]

I guess I need a 55l sender unit then,

Thanks guys

[smithy318i]

all sender units are the same.

the guage inside the cluster is different.

[Morat]

Could someone tell me what you expect to see on a gauge with mismatched senders?
I'm really confused with my setup. The car was bought off ebay with no history and it has had a pretty dodgy past so it might have had new clocks.

The tank has two senders, both of which seem to be working (they move, signal changes between full and empty etc). The gauge reads full when the tank is full, and falls rapidly to empty when the tank is about half empty/full. From there it stays on empty until the warning light comes on at about 12L remaining (I can get about 50l in according to the pump at that point).

Is it a mismatch between clocks and senders? or should I be looking elsewhere?

edit E reg 325i Touring, facelift.

[Brianmoooore]

Could someone tell me what you expect to see on a gauge with mismatched senders?
I'm really confused with my setup. The car was bought off ebay with no history and it has had a pretty dodgy past so it might have had new clocks.

The tank has two senders, both of which seem to be working (they move, signal changes between full and empty etc). The gauge reads full when the tank is full, and falls rapidly to empty when the tank is about half empty/full. From there it stays on empty until the warning light comes on at about 12L remaining (I can get about 50l in according to the pump at that point).

Is it a mismatch between clocks and senders? or should I be looking elsewhere?

edit E reg 325i Touring, facelift.

Pull the plug on the left hand sensor and short the wires on the plug together will be a quick fix.

[Gunni]

only single level tanks are 55l tanks you will need a 55l gauge as well,

I have a single level tank a dual level sender and 65l gauge and it always shows 30l more then the tank has,
I need a 55l sender and gauge and it will be fine,

[Royalratch]

I had some work done on a fuel pump that wasn't building pressure in the coldest days of winter - I used to live in Munich, yards from the BMW HQ / Olympic Stadion - Even took it for a service there once just for the novelty and they laughed at my right hand drive.

Anwyay, my low fuel light only comes on once it's way past the red, sat there for a bit and then comes on.

Basically, if I'm anal and want my warning light to switch on exactly at as the hand enters the red bit - what do I need to do?

Im guessing it's at the fuel pump end...

[Brianmoooore]

The fuel light is not supposed to come on when the needle enters the red section! It comes on when the needle reaches the light itself, and at that point you'll find about six litres or so left.

[Royalratch]

So it's perfect!


Many thanks.

[Brianmoooore]

So it's perfect.

Got a BMW badge on the bonnet, hasn't it?

[Royalratch]

Awesome... and other such superlatives...