UK Car Repair: daewoo lanos, deawoo lanos, daewoo lanos

Question
hi,my deawoo lanos "99" is fine when i first start up but after a couple of minutes it starts to rev a little higher than normal, it drives fine no noises or anything it just revs slighty higher, and it can judder a bit when slowing as if to much power is going through the engine.any help would be great.thanks

Answer
On first start up it should idle high, then, once the engine warms up, it will come down to normal -around 650 rpm. Is this what's happening?  If not then the problem is a leaking vacuum line or a fault in the auxilary air valve/stepper motor.  It should be relatively simple to have it tested at a local garage, ask them/or go on line, to see if Deawoo has issued a service bulletin for this problem.  Good Luck.