Hi, we had a similar problem with our gal (LHD '96 2.0 GLX) a few years ago in Germany. The ADAC (equivalent of the AA) came out and couldn't find anything wrong except a blown fuse (which happened to be for the secondary air pump which allows the cat to heat up quicker from cold start and sounds like a hoover - it had never worked since we had it and this noise was new to us !). It started straight away and worked - until the next morning. Checked the fuse expecting it to have blown but it was fine ! Got the ADAC out again, wouldn't start - he reckoned it would be the Engine Management Computer so transported it to the local Ford garage. The Ford garage thought the same, but couldn't find anything wrong ! They checked out the coil packs and said they seem fine except the rear one smelt burnt, so they replaced it and it's been fine ever since. The only other thing they said was quite common is if the scuttle water gulleys get blocked by leaves, etc. then water can get into where the Engine Management Computer is (apparently). Hope this helps - can't really suggest anything except calling / joining the AA (sorry). Good luck !