Spitfire 1500 - Fuel Gauge Sender

[Anglefire]

The fuel gauge on my car has been replaced and hasn't read very well for ages- doesn't get anywhere close to full when it is and doesn't indicate empty either!

So this afternoon, as I had run the tank down a fair bit (Though less than I first thought!) I dropped out the sender and eyeballed the float and adjusted it by bending the wire - both down a bit and towards the back of the car - as I think it was hanging up on the front edge of the tank where it expands.

I also measured the resistance - extreme reads of 30ohms and 240ohms - I thought standard was 20 and 200Ohms so not sure how much that will affect anything and even if you can get a direct replacement!

Now is reading just under 1/2 full - the level is above the shelf inside the tank.

So I'm going to run it some more and see what happens - and I have a spare tank in the boot should I actually run out! 

[dougbgt6]

AF,

Have you checked your voltage stabiliser? The fuel and temperature gauges both attach to it, it reduces the voltage to around 10.5 volts to stop both gauges fluctuating. 

Doug

[Anglefire]

The stabiliser is ok - well I replaced it some time ago to an electronic one and the temp gauge is fine.  

[Anglefire]

It’s purely a mechanical issue I think. Just a question of getting the float in the right place. 

[Pete Lewis]

The float fouling is pretty common, there is not much to play with dodging the suction tube and tank sides

Easy to test the float just do it outside the  tank with it earthed and do a fully up fully down and see what the gauge says 

Pete

[Anglefire]

I'm happy enough the gauge works ok.

I have put the sender back in, but not clamped down and rotated it so the float would rise up and I couldn't feel any fouling and based on the position of the float eyeballing it on the outside and it looks about right!

[dave.vitesse]

The values of resistors used to test the Fuel and Temp set-up. Used in Smith's test box/equipment.

Full/Hot  =      20 Ohms.

Half/Normal = 72 Ohms.

Empty/Cold =  270 Ohms.

Dave

[Anglefire]

Mine was reading about 58ohms and shows just under 1/2 full.  Given the location of the "shelf" and the fact that the tank isn't linear but the sender probably is, its somewhere close. The empty point will be the key! Need to get out and drive it more!

[Colin Lindsay]

18 hours ago, Anglefire said:

The fuel gauge on my car has been replaced and hasn't read very well for ages

Is it the correct gauge for your model? There are variations and even though the face looks similar, the readings can be way off... as you've found.

[Anglefire]

I should have said sender. Sorry. 

[Pete Lewis]

Yes a moving iron gauge sender on early cars is very different operation to stabilised

But are all 6 hole not bayonet ring  fitting

Pete