Thread: Fuel gauge acting a little weird.

You need a new gasket/ring.
They swell over time.( especially if you use fuel with ethanol)
Regards PhilipA

Damn that ring! I remember that one too(on bros TD5).

If you can remove the sender again, try to tip all the diesel in the bowl back into the tank if you can.
The move the floaty in as smooth (slow) motions as you can, whilst watching the dash gauge.

IIRC there is a slight delay between the movement of the floaty and the reading on the gauge too.
Brothers was acting weird too, always showing less than it'd actually have, so much so that he thought it only had an 80lt tank.
Add to that issue some previous idiot jammed a the plastic neck off a jerry can into the filler neck of the D2 too .. and it was hard to fill and it wouldn't 'fill'.
We changed the unit as we thought fuel pump was gone, but in doing so you automatically also get a new float assembly too!
New one works perfectly.
So most likely with his old unit(I still have) is that the resistor pack that gives signal to the BCU to give a reading on the gauge was borked.

From memory(of this sender design) it has the resistor sliders on the outside, so you can see the, top end of the float arm. If you get the unit out again, maybe give the exposed bits of resistor metal a bit of a cleanup. Light sand with emery and or contact cleaner or carby cleaner or something.

Originally Posted by PhilipA

You need a new gasket/ring.
They swell over time.( especially if you use fuel with ethanol)
Regards PhilipA

Yeah probably should, I will probably order a new sender unit and gasket, some different pricing on these units, local independent dealer as them at $560+ ouch! one's on eBay $112, anybody had any experience with cheaper one's?

Originally Posted by AK83

Damn that ring! I remember that one too(on bros TD5).

If you can remove the sender again, try to tip all the diesel in the bowl back into the tank if you can.
The move the floaty in as smooth (slow) motions as you can, whilst watching the dash gauge.

IIRC there is a slight delay between the movement of the floaty and the reading on the gauge too.
Brothers was acting weird too, always showing less than it'd actually have, so much so that he thought it only had an 80lt tank.
Add to that issue some previous idiot jammed a the plastic neck off a jerry can into the filler neck of the D2 too .. and it was hard to fill and it wouldn't 'fill'.
We changed the unit as we thought fuel pump was gone, but in doing so you automatically also get a new float assembly too!
New one works perfectly.
So most likely with his old unit(I still have) is that the resistor pack that gives signal to the BCU to give a reading on the gauge was borked.

From memory(of this sender design) it has the resistor sliders on the outside, so you can see the, top end of the float arm. If you get the unit out again, maybe give the exposed bits of resistor metal a bit of a cleanup. Light sand with emery and or contact cleaner or carby cleaner or something.

When I regain my energy for another go I will , damn thing ruined my day, it's funny the two items that have given me trouble on the car are a Toyota starter motor and BMW satan inspired locking ring.

Thanks for the prompt input though everyone, I will endeavor to get to the bottom of it.

Originally Posted by The Grooving Pict

Yeah probably should, I will probably order a new sender unit and gasket, some different pricing on these units, local independent dealer as them at $560+ ouch! one's on eBay $112, anybody had any experience with cheaper one's?

Is the sender unit available separately from the pump?
The costs you quoted indicate that it is for a complete pump.
The non-genuine pumps are a big gamble, with the odds stacked against you.

Check the electrical connector on the top of the sender unit. It is prone to fail. When the contact is not the best it can overheat and lose contact at all.

Regarding the fitting back together - first time it took me a couple of hours too. Then I found I was doing it wrong. I did have the rubber ring fitted on top of the pump and was just pushing it together to the top of the tank. Actually the lip of the rubber ring needs to fit inside the tank. So first put the ring on the tank (with the lower lip inside the tank) and then stick the pump inside the already fitted rubber ring. Refitting the big metal nut back should be very easy then.

Oh and the fuel level sender is not available separately from the pump assembly. But can quite easily be replaced (soldering or crimping needed). Beware that there's three versions of the TD5 pump differing just in the fuel level sender - because of different fuel tank shapes. Fortunately they (at least the original ones) have different colours of the top part - D2 being white, Defender 110/130 black a Defender 90 gray.

Originally Posted by pojir

Check the electrical connector on the top of the sender unit. It is prone to fail. When the contact is not the best it can overheat and lose contact at all.

Regarding the fitting back together - first time it took me a couple of hours too. Then I found I was doing it wrong. I did have the rubber ring fitted on top of the pump and was just pushing it together to the top of the tank. Actually the lip of the rubber ring needs to fit inside the tank. So first put the ring on the tank (with the lower lip inside the tank) and then stick the pump inside the already fitted rubber ring. Refitting the big metal nut back should be very easy then.

Oh and the fuel level sender is not available separately from the pump assembly. But can quite easily be replaced (soldering or crimping needed). Beware that there's three versions of the TD5 pump differing just in the fuel level sender - because of different fuel tank shapes. Fortunately they (at least the original ones) have different colours of the top part - D2 being white, Defender 110/130 black a Defender 90 gray.

Sorry about not acknowledging this post pojir.....I have been away a couple of weeks. Thanks for that advise about the lip of the seal...the other thing I forgot to mention is, when I got the sender unit out and unplugged the electrical connector there was diesel in the socket, I cleaned and dried it out, and cleaned it with isopropyl... just curious to wander what could happen there, would it cause an issue further down the line or not?