It does have a boosting problem i haventmentioned - it jumped from 7psi - 12si no bleed valve, acuator is secure? Amal valve piped up std.

I'll check the vacuum to makesure! it is a collins guage remember

The flap as far as im aware does bob up and down when cranking, unsure by how much as im usually starting it while someone holds the flap

No it idles rough, and if you touch the throttle the revs drop and it dies, you cant rev it. . unless you do it VERY VERY slowly after bout 10 secs it can be reved, but revs still fall if you hold the throttle, once warmed up you wouldnt know their was a problem.

Starts fine when hot! runs fine also.

Dont know about fuel pressure, To check do i undo a bolt on the fuel filter?

No dump valve.

Thanks for the help