Do I need a return to my fuel tank from the fuel rail, or can i get away with just a return to the swirl pot?

I would say to tank, as the amount from pump and return could be too much for the swirl pot?

Suppose it will depend on sizes though, of swirl pot and how much fuel pump is pushing in etc?

it should go back to the swirlpot from the rail, then there should be a separate return from the swirl pot to the tank.

And I would say swirl pot, as the amount of fuel the HP pump shifts will outstrip the LP pump feeding the swirl pot?
There should be a return/bleed from the top of the swirl pot to the tank anyway.

If you're using a swirlpot, it's usual to have a return from the fuel rail to the swirlpot and then a return from the swirlpot to the tank. If you don't have a return from the 'pot to the tank then there's no way for gas to escape from it.

This might help

Diagram is great.

Out of interest what kind of low pressure pump do you use? Could you use a facet red top or similar?

May go to MX5 power after IVA (currently xlfow) so would need the swirl pot set-up. Tank is already set up for injection set-up.

I'm fitting a Puma 1.7 Zetec in my car, looking to use a Posiflow pump for the low pressure as I have one lying about - http://www.facet-purolator.com/posi-flo-pumps.php - cheaper than the facet red tops and should do the job upto 175 hp injection.

Oh cool - that's what i currently have fitted. That can stay.

Thanks.

I thought as much!! I was hoping I wouldn't have to run another fuel line along the tunnel back to the tank! Oh well!