hey man, u need to pull the air intake pipe off the throttle body, located behind the engine which has the throttle cable connected to it, once you have disconnected the air intake pipe you will see the butterfly that controls the air intake. buy some carby cleaner and scrub the inside of the throttle throat and buttlerfly, opening and closeing as u do so. once you have cleaned the majority of the build up off, reconnect the airintake pipe and start the car, giving it a few good revs and take it for a run to get rid of the excess carby cleaner... hope this works, as i had the same problem in my 1999 astra... good luck ~harlz~
~harlz~
October 2005