When car is warmed up, car is idling very high, about 1,500 guestimate (without rpm-meter).

Also, it's giving really bad mpg, even driving like an elderly - £10 gets about 40 miles - I got more in my V6!

Worked out - currently getting 25mpg from my 1.3.

Vacuum leak?

Would this affect the mpg?

I was going to sort the valve clearances out today but lost my feeler gauge (even though it's been in my cupboard for months).

A vacuum leak would cause the high idle, and mess up the fuelling.

Check all hoses from the manifold proper,?

Thanks, I'll check that now!

No leaks - changed all the hoses anyway. I've noticed pressing against the throttle lever (the plastic one connected to the throttle cable) lowers the rpm.

Can't think of what this could be - lambda sensor? I don't want to spend anymore really on a car I only bought because it needed nothing buying for it and for it's economy, and it's doing neither.