Trying to get my S1 engined Escort up and running but I can't get it to stay running!

What happens.......


Starts from cold, but wont't idle, lots of revving needed to keep it running otherwise it cuts out.

Try and take it around the block, it cuts out.
This time it won't start..... leave it for a few minutes and it starts and for only a few seconds before cutting out....
(much more badly behaved when warmed up)


Also bear in mind it's all home built and wired and I haven't been able to get it reliably running yet.
Give me your best shot!