Scirocco Register

Hi
A friends Rocco is over-running (dieselling), keeping running for a few moments after the ignition is switched off. It's also idling high when started from cold, and still runs fast when warm, but if he stops the engine and re-starts it, it runs fine. There is a smell of fuel, as if it's over-fuelling.
I was told it could be the coolant temperature sender at fault. I changed the Waxstat, just in case, but that didn't fix it.
Any ideas?

Thanx
Phil

Have you checked the timing, Can cause the running on.

yeah, when it first started happening, I thought it maybe worth just adjusting the carb, but it only seems to play up when the engine is cold.
It idles fast on startup, then still does it when the engine is warm. However, if we stop the engine and re-start it, it seems to idle ok, but still over-runs.

Anyone know exactly where the coolant temperature sender is on an EX engine? I'm gonna bite the bullet and change it anyway.
I've got a Haynes manual, but its not being very helpful as to where exactly it is.