Originally Posted by
fiend
The problem with your door is the central locking motor, the spring that pulls the handle back down has probably broken. Its easy enough to change (only 1 spanner in the haynes manual).
You can get a new petrol cap on Ebay for under £10 posted..
http://cgi.ebay.co.uk/Locking-Fuel-P...item3a4caea56e
Or go to Ford and they can supply a genuine one with the correct barrel to match your current key.
Definately agree with the above on the spring issue, my lad had to change the spring in his twice in 6 months because they are that fragile.
Fiddly job but just take your time.