[Engine] self revving

[emmerson]

1999 1.8 petrol, goes well, except for an occasional blip, where it revs by itself, up to about 2500, which is disconcerting in traffic! If I dip the clutch to avoid hitting the car in front, it can then stall, but restarts OK, and ticks over at about 900rpm. When it revs the throttle is against the stop, so it's not a sticky cable.
Any ideas, oh fellow sufferers?

[Gadgetman]

One of the sensors on the throttle housing, possibly.
Or even one of the cables going to the sensors.

[ffrenchie]

Throttle position or mass air flow sensor. Our Kia used to do the same thing and it was the TPS, it's a potentiometer in a plastiic housing on the side of the throttle body usually and not expensive if you buy a generic one.

[emmerson]

Thanks boys.