Weird fuel sender behaviour

[Ozclay]

Am a first time poster so please forgive me if this has been answered somewhere else (have looked without luck so far). My fuel gauge seems to only register half a tank even when full. I removed the sender to check if it was a faulty unit but, when removed from the tank, seems to work fine. Gauge goes all the way to full and drops to empty (fuel warning light activates as well) and yet I still get nothing more than half a tank reading once reassembled. Any thoughts? Thanks in advance for any advice and apologies if this becomes a "doh" question.

[Marco Polo]

Did you check to see if the float "floats"? It may be perforated allowing fuel to enter and causing it to sink, hence the low reading. regards, Raoul

[Ozclay]

Thanks Raoul. I tried that and the float does not seem like it has a leak or hole that would cause it to sink. Will take another look however. I appreciate the feedback.

Clay

[SaskStag]

Welcome fellow Canadian!
I bought my Stag from someone in Kelowna, but it was supposed to have spent some time in the Vancouver area.

Mine did the same. You could try replacing the voltage stabiliser, its attached to the speedo behind the instrument gauge. I got a solid state one off Ebay which works fine and easy to fit. Gauge works now.

http://www.ebay.co.uk/itm/SOLID-STATE-VOLTAGE-STABILIZER-TR4-Dolomite-GT6-TR5-/130875496696?pt=UK_CarsParts_Vehicles_CarParts_SM&fits=Car+Make%3ATriumph&hash=item1e78c998f8

Take care
Tanya

[Ozclay]

Interesting thought Tanya. Will spend some time to look at the gauge in more detail on the (hopefully rain free) weekend. This is my second Stag (first in Australia; now an LHD in Canada) and no matter how much I think I have them figured out, there is always something new. Thanks again.

Clay

[SaskStag]

We're still waiting for the snow to go!!
Tanya

[flying farmer]

If your temperature gauge reads low as well it could well be the voltage regulator, I have just replaced mine as it only read 3/4 when full, and normal running temp has gone from 1/4 to half way up the gauge.

Neil

[V Mad]

Try an easy test to eliminate the suspects. Remove the lead to the sender and short it to earth. If the gauge then reads full the sender is at fault.
If gauge still only reads half, then its either gauge of regulator. If temp gauge works OK then regulator is rpob OK, which leaves the gauge as the culprit.

[Ozclay]

Thanks everyone. I will do some work over the weekend and report back once I, hopefully, find a solution. I appreciate the prompt and learned response from everyone so far. Thanks again.

Clay

[Ozclay]

Thx V Mad. Did what you suggested and it looks like it is the sender unit itself. Earthed the sender lead and the gauge rose. Back to usual connection, the gauge reverts to half. Plus side is that rules out the gauge and the voltage stabliser. Downside is a sender is more $$ than a stabiliser. Sigh. Oh how we love our Stags!

[SaskStag]

You can have my old sender if you want. I put in a new one as a routine job. It was working.
Tanya

[Ozclay]

That would be awesome Tanya. I will PM you and we can work out the details. Stag owners helping Stag owners. Gosh, I sound like a Home Hardware commercial!

Sorry folks, a bit of a Canadian joke there. :-)

Clay

[Ozclay]

So...an update. I purchased a new fuel sender unit, only to find the gauge continues to read no more than 1/4 to 1/2 full despite having a full tank. Curiously, the needle will rise when the sender is outside the tank although it is extremely sloooooow in registering anything on the gauge. Thinking the new sender is not the issue (the results are no different to the old one frankly, I purchased a new voltage stabilizer as suggested. Well - and you can see this coming - nothing changed. Gauge still reacts slowly to the same level, despite a now-near full tank. My assumption is, after all of this, the gauge itself. Any further thoughts/ideas before trying to find a replacement Mk2 (Federal) fuel gauge and where, if necessary, a reliable and reasonable place to pick one up without paying an arm or a leg? Thanks all for your help and feedback. This forum and your insight has been a Godsend, believe me.

[stag-phil]

Hi Clay
Just a thought but have you checked the wiring?

Not on a Stag, but a few years ago I had a similar problem on another car. After replacing the sender and fuel gauge the problem was still there so I connected a cable from the sender directly to the gauge and it worked. I then traced the problem to a rusty bullet connector.

Might be worth checking before sourcing a replacement gauge.

Phil

[SaskStag]

Hi Clay,
I have an old fuel gauge you can have. Yes, I did check before I wrote this; it's now sitting by my laptop! I don't know whether it works. I bought it from Ebay cheap for the chrome bezel, and I've reused the glass. I can bring it with me next week if we can meet up, or I can mail it?
Tanya