v reg saxo 1.4 non starter?

V reg saxo 1.4 coast/vtr lookalike thing, anyone have any idea what to try next, she turns over but will not fire now at all. it was very intermittent at first then got worse, ie some days would start ok then next day nothing, now its completely knacked. have changed ignition column aerial thing, cps, black relay under ecu and now an £85 ignition coil pack and still it wont start. any ideas much appreciated cos im stumped now.