My daily driver has developed a problem. It was fine on Friday going to and from work. I left it parked on the road to keep the drive free for the window cleaner. Later in the evening I came to move it onto the drive and it wouldn't idle, the revs just dropped until it cut out. I restarted it a couple of times and it was the same. Then I gave it some revs for a while, gradually backing off the throttle to lower the revs bit by bit thinking it would be OK after a minute, but no. with no throttle input, the revs drop to about 500 and then it dies.

does anyone have any experience of this? What are the things to look at? Ta!

Had a bit of this a while ago, turned out to be the ICV, fed it some carb cleaner and it started behaving again.

Idle Control Valve sounds like it might have something to do with it! Cheers!

super golf had the same problem.... cleaned out the bits and its been fine for 4250 miles in the last 3 weeks

So I take off the air box to see if I can locate the idle control valve. Next to the throttle pot is something that looks like a likely candidate, so I open the throttle with one hand and put a finger from the other down through the butterfly to see what's what. My finger comes out coated in the blackest stuff I've ever seen. Is there meant to be grease here? The throttle feeds into a plenum which feeds the manifold going to the engine. The fuel injectors are at the end of the manifold tubes. I doubt fuel ever gets to the butterfly. so I start the engine to see what's what and it runs. I put the air box back on and it still runs. No Idle problem at all. I'm concerned by the grease. why would it be there of all places?

It will be the crankcase ventilation - the intake pulls vapours from the crankcase in normal operation.