There's a section on here www.rsbible.co.uk Double click on the Escort S2 section and there's a tab for EFi conversion.

Another thing that may help, A mate i sold a FRST engine to put it in a XR2i a while back and just changed the engine loom via a main plug and just change the ECU and it ran fine, The only thing it didn't have was the wiring for the Amal valve which is no big issue,

Could just get a full XR3i EFi loom and do the same.