External PI pump

[trackerjack]

Hi folks,I am building a one off Lotus Sevenesque special using an MX5 Mk 1 engine with turbo and have a question for the smart ones on here.
The standard fuel tank will not fit so I have to source another solution and have come up with the same answer as Bosch used on virtually all cars that use their system.
Can I use the pump and filter that comes with a Ford which is outside the tank.
Am I right in thinking that pressure is controlled by the system and the pump just supplies more than it needs and just returns it to the tank after the correct system pressure has been reached?
Or will I have to fabricate a tank that utilises the standard pump?
Hope you guys can help.

[robgee1964]

You are quite right, the pressure in the fuel rail is regulated on the engine, and the excess simply returns to tank.

So long as the pump is designed to run an EFI system then for the MX5 engine it will be fine. Your only issue with an external pump could be priming it, should the tank run dry. But plenty of cars manage, for example some of the old jaguars got round this by mounting the pump beneath the tank.

Some later vehicles do have a returnless fuel system, and for one of these you would need the right pump. But an early MX5 is not one of them.

[trackerjack]

Thanks so much for the reply I have a new pump and it is the easiest solution but I wanted some support ta. Fords chuck the pump under the tank in the road dirt! but my car will not have to endure much of that as it will be a fair weather toy.