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fuel gauge

Posted: Sat May 26, 2012 12:08 pm
by stefan442
Followed the factsheet and I linked the cables but instead of going up the reading went down. I continued anyway, so I put a new earth from the chassis down to one of the fuel sender bolts and my reading went up steadily to just over half a tank. Which is quite a bit considering it was hovering just below the first mark proir to me doing this. Now I'm wondering what's right and what's wrong!

On to the Headlamps tomorrow :) its beer time now

Re: fuel gauge

Posted: Sat May 26, 2012 5:15 pm
by winchman
I have also seen this
Re check alls clean.
Short out the two wires going to the sender, after a couple of mins the gauge will go to full.
If this works you have high resistance in the metal and connections in the actual sender, its easy to fix I can take a picture of a repaired sender after the weekend.
Basically you run an extar wire fron the sendeer oplastic bit in side the tank to the lid of the sender sound hard but once you see the picture its easy

Re: fuel gauge

Posted: Sun May 27, 2012 1:24 pm
by stefan442
please send pics :)

The gauge is just reading over half.... seems stuck there. Need to get this sorted before I drive to the south of France next week!

Re: fuel gauge

Posted: Sun May 27, 2012 3:59 pm
by winchman
stefan442 wrote:please send pics :)

The gauge is just reading over half.... seems stuck there. Need to get this sorted before I drive to the south of France next week!
I will try and take some tomorrow.
But Take the sender out, look at the white plastic thing that surrounds the float connection, One of the screws that holds it on makes contact with the circuit board so it can earth out, if you measure the resistance between the mounting screw and the top of the sender on the out side of the tank you will find high resistance.
I ran a small cable from this screw to the top of the sender unit, I drilled a hole in the lid and bolted the wire to this hole using a rubber washer as a seal. on the outside I connected the other end of the screw to earth, then it works find.
Its best to replace the short fuel hoses at the same time as these will be starting to perish

Re: fuel gauge

Posted: Sun May 27, 2012 5:17 pm
by daveblueozzie
There are a few ways to re-earth the tank and sender, one from the lip of the tank to the chassis, the other from the wires on top of the tank to the screws surrounding the sender (the one i have done on about three bongo's )
http://www.igmaynard.co.uk/bongo/forum/ ... uel+sender

Re: fuel gauge

Posted: Sun May 27, 2012 5:51 pm
by winchman
daveblueozzie wrote:There are a few ways to re-earth the tank and sender, one from the lip of the tank to the chassis, the other from the wires on top of the tank to the screws surrounding the sender (the one i have done on about three bongo's )
http://www.igmaynard.co.uk/bongo/forum/ ... uel+sender
This normally works fine but I think Stefan has poor resistance in the connections between the sender module ( think its just a variable resistor) and the top mounting plate, I have only seen this once but just fitted an aditional wire and it worked fine. The pipe work had a few small bits of corrosion on it so I felt this was causing high resistance and a false empty reading.
Stefan, the very first job is to check the resistance as per the link above then you can be certain exactly whats up.

Re: fuel gauge

Posted: Sun May 27, 2012 6:49 pm
by stefan442
This will be the first thing i do tomorrow after work, been nursing a hang over all day! #-o

Cheers for the info, ill let you know how it goes. I've searched the forums a bit today and found out other snippets of info.

Are the bolts 4mm? I remember it being small, they need changing as the heads are very rusty. Ill pick some up at work tomorrow, might even have some in the van!

Re: fuel gauge

Posted: Sun May 27, 2012 8:13 pm
by winchman
Heres the top with the new nut and bolt
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Look at the thicker cable that runs from the screw on the plastic bit to the new nut and bolt on the sender top.
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This will put the resistance back to how it should be so the gauge will read correctly, most Bongos just need the additional earthing, but I did find one that needed this as it had a bit of corrosion in the pipes so this altered the resistance.

Re: fuel gauge

Posted: Tue May 29, 2012 4:50 pm
by stefan442
Got one 4mm bolt that just won't come out. Tried using my grips on it but it.just won't turn.... is it safe to drill out? Its a diesel...

Re: fuel gauge

Posted: Tue May 29, 2012 5:47 pm
by winchman
Yes
Just take your time and dont let it get too hot
If you judge the size right you will just drill the head off allowing the sender to come out.
If you dont want to drill it, try soaking for a few days in WD 40 etc, give it a few taps with a hammer and a good small pair of mole grips should shift it, or snap it off, if you were local I would just come and do it :D

Re: fuel gauge

Posted: Tue May 29, 2012 6:59 pm
by stefan442
winchman wrote:Yes
Just take your time and dont let it get too hot
If you judge the size right you will just drill the head off allowing the sender to come out.
If you dont want to drill it, try soaking for a few days in WD 40 etc, give it a few taps with a hammer and a good small pair of mole grips should shift it, or snap it off, if you were local I would just come and do it :D

Muhahaha, i drilled it out like a boss. I just drilled the head off and there is a stud left. I will drill it out fully and tap it eventually, but i just wanted the quick fix. The brass bolts are temp till i can get my hands on some 4mm stainless bolts. I heat shrinked the cables on top of the sender, the short pipes seemed in ok condition.

Spent most of my time messing about the the last bolt, couldn't grip it. Very soft stuff them bolts.

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Seems like there is about half a tank in there to me, when i turned the ignition on it went up slowly to just under half a tank. Which is much better than before i did anything to the thing. :D

Re: fuel gauge

Posted: Tue May 29, 2012 8:01 pm
by winchman
Well done, its easy once you have done one, most I have seen just require the earth outside the tank you have been unlucky as I was but should be fine now.

Re: fuel gauge

Posted: Tue May 29, 2012 8:29 pm
by daveblueozzie
Another one for the fact sheets by the looks of it, well done. =D>