The engine is totally standard and yes it still has the airbox fitted to it.
I think cleaning the Idle value, changing the oil and air filter are the first jobs on the list.

I had a look for the Idle control valve and couldn't locate it (sorry I'm I real novice where engines are concerned).

Do you have, or know where I can get hold of an diagram/ picture of the I4 so I can work out from that were the stuipid thing is?

The I4 does have what looks like a control value attached to the airbox so was unsure as to what that was.

I have taken some pictures of my engine and can post them later this evening if this doesn't make any sense.

Cheers for all your help on this.

Roy