Hey all,

I'm measuring my fuel sender on my Tiger Avon, I measured the resistance @ 239.30 Ohms. I then emptied the tank, removed 2 litres of fuel. The resistance fell to 239.20 Ohms.

Does this seem correct?

I thought 2 litres would change the resistance more??

Jason.

maybe the float has reached the end of its travel. so shows empty for 2l and under. what does it read full?
ps to fix it you may need to adjust (ie bend...) the arm

All

Following my earlier post I have decided that my fuel sender makes no logically sense.

I have emptied my tank and measured the resistance at 281ohms. I put in 5 litres if fuel and measured 320 Ohms. At this point I was feeling very pleased with myself and expecting an increase in Ohms relative to fuel. I then put another 5 litres (giving me 10 litres of fuel) and my 'stupid' fuel sensor decided to wreck my Sunday afternoon with a reading of 172 Ohms.

So to recap;

0 litres 281 Ohms
5 litres 320 Ohms
10 litres 172 Ohms.

This has also changed to when I measured an empty tank yesterday.

If I could swear on here I would!!! How am I suppose to logically work out how much fuel I have!!!

Advise, words or wisdom or sympathy welcome.

Jason.

If you have isolated the sender from the loom and the float is raising and falling as it should. Then yes, that is confusing. Remove sender from tank. Check readings once more by moving the float up and down manually. If it's still the same replace.

Thanks Mr Frog.

Yeah the sender is isolated, to remove the sensor I have to drop the tank out so was trying to avoid that.

I might take the fuel back out and try again. Maybe when I took the 5 litre reading the measurement wasn't settled. I have also gone the other way and measured the gauge and it seems the gauge is configured to 280ohm Empty and 40 Ohms full. This would match my 0 litres and 10 litres reading,

Is there a delay in the sender to settle? How reactive is the sender normally.


Jason.

since most of these senders are a wipe contact to the resistance, it may just need a bit of cleaning.
the easiest way to do this is just move the float up and down a few times.

quote:

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Is there a delay in the sender to settle? How reactive is the sender normally.

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Ok,

I have removed my fuel tank, and the fuel sender doesn't seem to have any way of removing. There's loads of silicon around it but surely there's a way to remove it.

Jason.

Don't know how to put a photo in?

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Originally posted by Huttojb
Don't know how to put a photo in?

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All

Please see below, My fuel sender - do i just remove the silicon and pull it out?



GenFuelSender

(If it works)


I have also attached a picture of my car - because I can!!


huttojb_GenTiger


huttojb_GenDash


huttojb_GenCockPit


Jason

Three things it might help you to know:-

Silicon and petrol doesn't mix. It goes to jelly.

All electrical contacts should be clean. This is especially important when a gauge is trying to measure small differences.

To allow for voltage fluctuations some gauges require a lower feed voltage. I have a Smiths gauge in conjunction with
a Ford sender and the gauge is fed by 9.9v/10v.



HTH
Paul G

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Originally posted by 907

Silicon and petrol doesn't mix. It goes to jelly.

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Thanks all for your help, just an update.

I have now cleaned the connections and exercised the wiper. This has resolved my intermittent and unexpected reading.

Just a few questions,

The sender was fitter into the tank and had some sort of silicon around it. What silicon / glue / fuel resistive sealant I can use. The sender is not a great fit and it is required.

a very quick search for "petrol safe sealant"
suggests
hylomar blue

edit: remember thats only a sealant, not a glue

[Edited on 3/10/16 by gremlin1234]

Your sender looks like it is probably from a production car of some sort? possibly a Sierra? It should have a fuel proof "O" ring as a seal sitting in a groove on the underside of the mounting flange .

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Originally posted by rusty nuts
Your sender looks like it is probably from a production car of some sort? possibly a Sierra? It should have a fuel proof "O" ring as a seal sitting in a groove on the underside of the mounting flange .

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Also - I am measuring the resistance fromt the fuel sender by using a 5V signal and measuring the voltage across the potential divider.... as I have been advised, petrol goes **BOOM**!!! Would this be ok?

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Thank you; I ahve just looked at;

https://en.wikipedia.org/wiki/Vapor_lock

Is this why there is a gas bleed valve (not sure what to call it) on top of the fuel tank to remove any harmful gas...

So in your opionion providing a 5V to the fuel sender should be ok - I beleive this is what the gauges do, because I don't know how else you would measure the resistance?

quote:

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Originally posted by Huttojb
Thank you; I ahve just looked at;

https://en.wikipedia.org/wiki/Vapor_lock

Is this why there is a gas bleed valve (not sure what to call it) on top of the fuel tank to remove any harmful gas...

So in your opionion providing a 5V to the fuel sender should be ok - I beleive this is what the gauges do, because I don't know how else you would measure the resistance?

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quote:

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Originally posted by gremlin1234
explode

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quote:

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Originally posted by Huttojb

quote:

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Originally posted by gremlin1234
explode

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YOUR NOT HELPING - lol!!!!!

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