The self diagnostic test on the dashboard will not tell you anything,these codes that show from that test are test codes when the car is built so those building the car can check all is ok with the connections and bulb lights etc.
The engine running fault codes can only be obtained by pluging in a fault reader in to the socket under the steering wheel behind the cover plate.
These codes are the only reliable fault reading codes for the running of the engine.
Because of the dampness try a spray of wd40 in the both ends of the HT leads if it improves replace HT Leads - plugs and air filter.
Hope this helps.
OK thanks for that advice. I was thinking of getting one of those fault readers off ebay, does anyone know exactly which one I should get? Also, fault codes that people appear to be getting (i.e. DTC-9202) don't seem to appear on any of the fault code lists I have found on the internet (i.e. here: http://bbs.rsownersc...ad.php?t=150460 and here: http://www.fordst170.../dtc-codes.php), am I missing something?
It appears (although I am not certain yet) that the problems seems to be related to how long the car is left without being used. Obviously the longer I leave it, the worse it is. Over night I can start it with a little throttle persuasion but if left 2 nights I may have to crank it over with my foot flat to the floor (I have yet to leave it 2 nights since this first happened).