Daimler Sovereign series 2 fuel tank issues

[dsrenovations590]

Hi there... I'm a newby so apologies if any or all of this sounds daft..

I have a '76 Daimler Sovereign...its great apart from an intermittent issue when swapping over fuel tanks... occasionally it just starts playing up inc cutting out, mis firing, etc... any ideas why this may be...?

[3.8etypephil]

There are a number of possible causes: faulty changeover switch (pull out the switch, check for correct continuity in both positions, and damage to the wiring behind), a faulty pump or poor connection to one of them, sediment or water in one of the tanks (the drain tubes at the filler neck can become blocked and allow rainwater into the fuel), defective pipework, are all worth checking to start with, in that order.
Does the problem occur under a particular set over circumstances, or apparently randomly? One side only, or both? When the problem manifests itself, what is the fuel gauge doing?

[dsrenovations590]

Many thanks for your helpful reply - and so quickly...

We were at the Silverstone Classic - all set for doing the Retrorun when this happened - your diagnosis lead us to being able to work out its water in the fuel - the right hand tank was just about fit for purpose - I guess once filled and kept topped up the water would have been at the top - meaning a trouble free day and a safe trip home... many thx again

Time to get it sorted now...!

[oldtimer]

DS,
You may care to obtain a CLEAR glass or plastic container and pour in a pint of petrol followed by an egg cup full of water and watch to see where the water settles ?

I'll say no more but will be interested in your conclusion

I was also at Silverstone with Tintin ,but on the Saturday in area 11 on Copse corner--thought it was a great day--- walked for miles and am absolutely clapped out today.

What colour is your car ?

Time for bed !

[oldtimer]

Just a quick PS , Is your '76 XJ on carbs or fuel injected ?