3 Litre fuel gauges

Before I go making new fuel tank intake pipes for the pick up unit  I would like to know if when the gauge show  empty (assuming that everything works as intended) the level in the tank has reached the shorter intake pipe (hence the need to activate the reserve switch) or whether in fact the tank is actually empty. The handbook only says that a gallon remains but makes no specific reference to the whether the gauge needle is actually on empty.  I would members experience with the gauge.  Richard (Melbourne) Posted by RichardWallach 15/06/2014 09:48:45

Hi, when my TD21 gauge goes to "empty", it runs out virtually immediately and I have to pull the "reserve" switch - so I think it's the former situation in your question. Posted by Philip 15/06/2014 13:59:05

My impression from running two original TD21s is that EMPTY means empty and you have to activate the RESERVE before the gauge actually reads EMPTY thus giving you 20miles to find a garage - which can be tricky these days. Posted by vaningen 01/08/2014 22:22:33

Reminds me of my 1967 Ford Mustang which would grind to a halt a few hundred yards after the needle hit E.  Happened about 3 times before the message truly sank in! Posted by johnlayzell 02/08/2014 14:54:56

I suspect every car is slightly different as consistency/repeatability would not be high on messers Smith/Lucas's agenda as they knocked out these uncalibrated guages/float switches by the ton.In my even poorer days I used the reserve function a lot and have no recollection of trying to judge when to pull the switch, the warning signs of a strong smell of petrol vapour (Why?) followed by a coughing from the engine were enough for me to initiate  the process, the car would always  keep going before picking up.  The following may be of help.  1 Check the system actually works ,the reassuring clunk of the solenoid is a good start, then see how far you can go before finally running out, see 3 2 Remember to switch it off after finding the elusive petrol station, nothing worse than going to switch to reserve a few weeks later to find you have already used it up and you are now really out, see3 3 Always carry a suitable can ,at least 5 litres, maybe more would be prudent as proper garages keep closing and you will burn half a gallon negotiating an out of town shopping complex to get to Tesco/Asda  4 Reserve to reserve is a fairly good method of checking your fuel consumption provided you note the mileage. Posted by Peter Martin 03/08/2014 13:21:35

I can now report my findings after having emptied the tank and experimented with different amounts of fuel in order to establish a base line for the reserve function. In my case when the gauge reads empty there is in fact a little over a gallon of fuel remaining. Whilst this generally accords with the Manual of Instruction there is the complication that when travelling uphill the petrol gravitates to the back and the  intake  starts to suck in air given the front mounted position of the pick up unit. I live in a hilly area so the problem is real in my case.  At least there is piece of mind as to how much fuel exists. There is also an added bonus of the tank being cleaned. Posted by RichardWallach 07/08/2014 11:01:46

I was interested that Peter notices a smell of petrol when his car runs out of fuel. My TC21 leaks fuel at quite a rate from the starter carb (dripping onto the heat shield covering the exhaust manifold) when running out of fuel. I know this as the car is not anywhere near roadworthy so the only time I have  started the engine is in the garage. Is this a feature of this type of fuel enrichment device or do I have a problem? Posted by drdowhitt 10/08/2014 22:53:57

My TA21 has the original Solex carburetor and there is absolutely no petrol smell when the engine is starved. It will be interesting to see how this aspect of the issue unfolds over the Bulletin Board. Posted by RichardWallach 11/08/2014 03:08:56

Jon,  It shouldn't drip. You have a problem!  I recently experienced fuel flooding out of the top of one of the tubes from the starter carb when the engine was warm. Turned out to be caused by worn out needle-valves in the float chamber lids causing flooding, exacerbated by missing breather-washers under the float chamber lid bolts, hence the fuel had nowhere to go but out through the starter-carb.  Cheers  Angus Posted by Angus D'Arcy-Drake 13/08/2014 08:18:23

Thanks, Angus. I will check that. Posted by drdowhitt 16/08/2014 08:20:59