At 40,000 miles (hot or cold) waiting for the coil light to go out and turning the key has lost its reliability. The starter motor works fine and using a slight touch on the throttle gets it going. Something has clearly changed and for 35000 miles it wasn't even necessary to wait for the light to go out or to touch the throttle. Is this a known feature and what can I check with amateur equipment? My thanks in advance for any tips.

A bit more detail could be useful? I'm having slightly similar problems in that sometimes (particularly when warm), it fires instantly, but other times (more commonly when cold, and having been left for a few days), it can take a couple of seconds of turning over. I am not getting any smoke, rough running, power loss or unusual noise/vibration - the rest of the time it's been running very sweetly. I've done a bit of google, and one possible explanation might be air squeezing in around where the fuel filter is joined to the rest of the system. I think the fuel filter is a consumable, did your problem appear shortly after a service?