Fuel gauge issues

[phillpot]

Aside from the sloshing about when cornering my gauge used to be reasonably accurate, but now it's only reading 3/4 when full and proportionally 1/4 lower as the level goes down.

A little question for all fellow TVR owners.....


Have you ever pulled he feed to the tank sender unit off and measured the voltage?

Would you like to go and pull the feed off and measure it?

I was expecting 12 volts or thereabouts (11.5 on my Taimar) but only getting just over 6.

Pretty sure I have 12V to the gauge, common feed to all gauges and the others are reading okay, but getting to the back of the gauges is, as many of you probably know, a right ball ache!

And there's no point if 6V is correct.

I've managed to find the sender feed wire in the loom behind the glovebox, stuck a pin through the insulation and tested, 6V, so no issue with cable front to back.

seems a huge drop for an iffy connection, could there be some sort of resistance built into the gauge? Somethings changed as it used to work

Faulty gauge, don't really know what's inside to go wrong?


Taking the sender unit out of circuit, putting the live directly to (a good) earth still only 3/4 so happy it's not a sender problem.


May be this is the answer........... clicky ...

[greymrj]

Thought I had a possible answer until you isolated the sender. Puzzled now. Gauges like that normally work or pack in completely. I suppose a corroded or loose gauge connection could be raising the resistance. That gauge is a b**** on the S1.

I will however add this bit of info as it may help someone else. I fitted a new sender and adjusted the float wire length and it worked pretty well. A few months later I noticed it seemed to be reading low, and then I noticed it showed under half when I had just fulled it. Next time it stayed showing almost empty. It was very carefully wired so it didn't seem to be outside the sender. Took the sender out again, the new sender float was 75% full of fuel! I cant even see the pinhole, it just weeps slowly out. Fortunately, as I am like Mike and wonder if things might come in again, I had the float of the old sensor. Back working again....for now!

[Oldred_V8S]

Just checked
6.6v on mine too Mike.

Voltage readings should be taken with the load connected and the circuit live. See if you still get the same readings as you did when you plugged the meter probes into the disconnected plugs.

Edited by Oldred_V8S on Wednesday 20th September 17:51

[phillpot]

greymrj said:

the new sender float was 75% full of fuel!

This was my suspicion Richard until I started prodding around with a meter

I'd even got a new seal and lock ring in ready, and knocked up a fitting tool.

phillpot said:

Would you like to go and pull the feed off and measure it?

Oldred_V8S said:

Just checked
6.6v on mine too Mike.

Thanks Paul, will have another look at it tomorrow

[TVRees]

phillpot said:

I'd even got a new seal and lock ring in ready, and knocked up a fitting tool.

Be careful, the three little lugs are not too strong. Speaking from personal experience after using my special tool, which almost deformed and removed all 3 lugs.

[mentall]

greymrj said:

Took the sender out again, the new sender float was 75% full of fuel!

The technical answer to your problem is here.
WARNING: don't read anything else you may find on this website!

[RayTVR]

mentall said:

WARNING: don't read anything else you may find on this website!

Nonsense, I just spent a happy half hour chuckling inanely.

I'd recommend the NASA moon landing fake in particular