I've done a few little jobs on it including the O2 sensor (original was rusty and had ford emblem so no doubt hadn't been changed for a while) and it seemed to start in open loop pretty well as it idled from cold at around 1100rpm ish, when normally it would be 800-900. I didnt test it however because there is this problem still apparent -

If you turn the key and try to start the engine straight away (i.e. as soon as pump kicks in) it will start on the button, but if you leave it on pre-ignition for a few seconds and then try to start it, it just turns over and never starts. The clock light is out so I doubt its the usual PATS issue - I'm thinking perhaps its related to fuel pressure?