9 replies to this topic

[Minisport7]

one of the two flanks on my fuel sender unit snapped off, so, I tried soldering it on. It snapped again. So, I decided to change it out for a new one.

I fitted the new fuel sender unit, connected the two wires from the fuel tank to the fuel sender unit but the fuel gauge now tells me I have a full tank (tank is near empty).

I've tried taking the fuel sender unit out and back in at least 10 times to see if something is in the way but still giving me full tank reading.

It's the zigzag fuel sender unit for Mini Cooper sport 2000, identical to the one I replaced.

Does anyone have any ideas??

Edited by Minisport7, 24 July 2017 - 10:59 PM.

[Sask_Mini]

You probably have the two wires that are connected to the fuel sender unit reversed.

[Minisport7]

Black wire into the plain flank. Black & Green wire into the flank with plastic around it.

[Sask_Mini]

Hmm, that sounds right.  The black wire is a ground so that should definitely be going to the uninsulated terminal.  This is a picture of mine just to confirm.  Ignore the red paint, the black is the top wire and black/green is the bottom wire.

 

[Minisport7]

Correct. I've attached the wires to the sender unit before fitting into the tank and it seems to work fine; all the readings are accurate.

When fitted, however, it shows as full tank.

[Sask_Mini]

Hmm, thats really strange, if it works outside the tank just fine then there should be no reason why it wouldn't work when you put it back into the tank unless something is causing the arm to stay raised. 

 

I fitted a straight arm sender unit to mine last year and didn't really have any issues with it aside from hooking the wires up in the wrong order, which gave me a false reading.  But that being said, my mini isn't a fuel injected mini like yours so there might be something else going on inside your tank that I haven't seen before.  

 

I can't remember from when I did mine, but there is only one way that the sender will fit into the tank right?  I remember there being some kind of notch that indexed the sender unit into the proper position?

[Minisport7]

There are four teeth on the sender that slot into the fuel tank (three big, one small)- giving it only one way it can lock in.

I don't know what's causing the sender arm to stay raised - I tried having a look from the fuel tank neck but it's too small to see anything.

Running out of ideas 😓

[Sask_Mini]

This might be a crazy idea, but what about if you tried to send a thin piece of wire or string down through the filler neck and out through the sender unit hole.  Tie the wire off to the float and reinstall the sensor.  See if you can move the float around with the wire/string.  

 

At least that would tell you if you can physically dislodge or move the arm around.  If you find you can't move it then I guess you will have to experiment with bending the arm a bit.  

[CityEPete]

As I've said in other threads you can't see down the later tank neck with the unleaded nozzle restrictor.

[Minisport7]

Fixed!!

I squeezed my head in the boot and had a peek through the hole where sender unit goes in, and saw that the fuel pump sits in the middle of the tank, and that's what the arm was getting stuck on. Had to enter float and arm into the tank as left as possible to clear the pump.

Thanks for everyone's input!