Fuel tank question (could be a silly one)

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ah
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Post Tue Feb 21, 2012 10:16 pm

Why has my tank got 2 sender units.

http://bmminiparts.com/DiagramView.aspx ... MOSP=47288
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Jim320i
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Post Tue Feb 21, 2012 10:32 pm

Sender & pump
johnl320
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Post Tue Feb 21, 2012 10:37 pm

Isn't it because you have the larger tank with no balance pipe underneath the prop so it has a level sender each side of the saddle tank?
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Brianmoooore
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Post Tue Feb 21, 2012 10:50 pm

johnl320 wrote:Isn't it because you have the larger tank with no balance pipe underneath the prop so it has a level sender each side of the saddle tank?
It is indeed! Levels aren't necessarily the same in both sides, so two senders are required, connected in serious, to provide an average reading.
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ah
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Post Wed Feb 22, 2012 7:33 pm

Brianmoooore wrote:
ah wrote: As you suggested, I shorted together the connections on the plug and the bulb lit up.So would the fault be somewhere round the fuel pump area.
Can only be a duff level sender unit then.
Remove the four small nuts and the washers under them, and lift the sender unit straight up and out. Have a container handy; it will leak fuel.
All E30 sender units that go with the in tank pump (i.e. facelift) are the same.
So does that mean I need to change both or just one,if so which one?
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Brianmoooore
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Post Wed Feb 22, 2012 8:35 pm

The low fuel switch is part of the sender that's slotted into the fuel pump.
Same part on all facelift cars, whether 55 or 62 litre tank.
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ah
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Post Wed Feb 22, 2012 8:44 pm

Many thanks Mr Moooore!
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Post Wed Feb 22, 2012 9:06 pm

Simon13
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Post Wed Feb 22, 2012 10:01 pm

Why is the connection between the two senders so serious?!