Fuel Filler Caps

[Steve]

Hi,

I normally just lurk on this list gleaning valuable information for the
more knowledgable posters.

However, I have a question! I'm currently fitted a Ford Zetec with a
custom fuel injection system to my Caterham 7. I've changed the fuel
tank which now has a fuel pump mounted inside the tank feeding the
engine via a high pressure hose. The existing fuel line is now used as a
low pressure return.

The fuel filler cap normally used with fuel injected Caterhams is
labelled as having a 'pressure release' facility. Is this absolutely
necessary in a fuel injection system? Surely the pressure in the tank
itself is no different to that in a carb based system? So the question
is :- Can I use my existing fuel filler cap - which makes not mention of
having pressure release?

Thanks for your advice,

Steve.