UK Car Repair: 1999 2.0 SRI Astra problem., coil pack, revs

Question
Hi Paul, my Astra is idling strange and not accelerating properly. The idle falls well below the 900/1000 rev marker and comes up and down occasionly. Sometimes it goes right but very rarely.
It feels like the car has a confused mix of air and fuel making it very sluggish and non responsive.
When cold, the car is very jumpy through mild acceleration.
Can you help me out?
Thanks, Marco.

Answer
Hi Marco, it sounds to me like you have a cylinder mis-firing. Start the car and allow to idle, bring up the revs very slowly and if you feel a vibration then you are running on 3 cylinders. I would suggest checking the coil pack and if your car has ignition leads(some do and later ones don't), replace them and the plugs. This should cure the problem, if not let me know - Paul