Funky fuel gauge?

[canuck]

I need your help chaps.

The fuel gauge in George is misbehaving. This gauge has always been 'odd' ever since I got the car 6 years ago. It read 1/4 when full,  half or empty when full then indicates as it should etc. I can never depend on it. With the dismally small capacity tank I always use the trip odometer to let me know when it is time to re fuel. 

  

Its latest trick is that the needle 'dances' all over the place very rapidly and does not stay in place long enough to indicate fuel level. 

Would the collective WE suggest this to be sender issue,  a gauge issue or bad connection between? 

Thoughts or ideas what can be the issue and ultimate fix?

Thanks

B

[noddy]

B,
First guess would be a faulty connection - especially with the 'dancing' needle! Also it is the easiest to diagnose.

If its not that, then try the guage - but more likely its the sender unit , which is tricky to get to and remove (I have done previously, but it takes time and patience).

Let us know how you get on,

Roger

[canuck]

Roger

Thanks for this.  I will do a bit more sleuthing about the car.

Yes, I think I did sort the connections when I first got George but will now need to be a little more thorough, the 'flippy' needle seems to be this 

You may recall, George had a very tough childhood and was treated to gravel roads most of his life, this was not kind to the under body.

The fuel tank has suffered abuse,

in fact the PO installed a plate to try to mitigate critical damage.  

I suspect the trouble may be lurking deep inside this tank but I have been shy to address this to date. 

The fuel sender is a 21G part number and of course this means Riley one-point-five specific. Do we know of a source for a replacement?

Thanks

B

PS: you can just detect my rebuilt/tweaked rear spring assembly in the background

B

[Mabel]

Bruce

Think badly behaving fuel gauges is a common problem if not a design feature and I'm with Roger in that it's the sender unit that is likely to be at fault. When mine's showing just less than a quarter full, it's actually nearly empty. So, I fill it to the brim and it's nearly showing Full but not as close the Full line that I'd like or it should be. Yes, I could fit a new sender unit but that's not the easiest job so I just keep an eye on the gauge and once it's less than half-full, it gets topped up again. Problem is that doesn't help in knowing how much anti-ethanol fuel additive to put in. That happens once I'm back home and if anythinmg I err on the side of caution and put just a bit less in than I think should be added.

[2robert4]

If you can confirm that the sender unit is at fault I seem to remember many years ago I replaced the sender unit from my Wolseley 1500 with a Mini Estate/Van sender unit I can't remember the part number but it began AAU8 I'm sure.
Regards
NP

[noddy]

B,

When I had trouble with mine, I bought a Mini sender unit - but it didn't seem correct, the arm was orientated incorrectly. To be honest I didn't look toO hard - so there may be a Mini one that does fit properly.

Anyway to solve my problem, I just very carefully dismantled and cleaned my old unit - which now works fine.

Of course you could always fit an extra fuel tank!

Roger

P.S. -rear suspension looks good Bruce!

[canuck]

Thanks chaps,

Obviously no shortcut to sort this.

I will start with cleaning and validating the connections at each end, tank & gauge. I have had the dash out (too often) so perhaps I did something to the wiring and didn't snug everything up again.

However if this does prove to be the sender in the tank I will need to take all this apart.  Judging by the state of my tank, this looks like a good winter project .

Roger, the auxiliary tank is a great idea, and I like. I would of course have to find a derelict Magnette ZA/B over here , ummm? then pick your brain for months, then fret over the filler tube location, etc. etc.  Perhaps easier to just roll the trip meter to zero at each fill.   

salut

B

[trymes]

Bruce: If you remember, when I got my car, a DPO had (out of desperation, I am certain) fiberglassed my entire fuel tank bottom, leaving me with a rusty, leaky mess. Tim T. was kind enough to UPS me a good tank, and I had it cleaned and painted before re-fitting the sending unit. If memory serves, the sending unit is a common item, shared with the MGA and others. The difference is the arm and float, which are Riley specific. My float did not, so I de-soldered it and fitted a float from a #2 Fuel oil tank gauge. Perfect fit and should be petroleum resistant! A "speed nut" from the local hardware store holds it in place.

If worse comes to worst, I think you could buy an MGA unit and either swap the arm/float or bend the MGA arm, or make a new one from some sort of stiff wire.