There are a few possibilities and things you can check;
Catalytic converter could be cloged. Check entire exhaust system for restirctions or glogs.
Check fuel pressure.
Check the air passage for dirty or clogged air filter and anyting else that might clog air flow.
The ignition coil could be weak or failing, test it and see if it is putting out proper voltage. I do not have any specifications on your car. It should have 12V to the coil, but I am not sure of the output which should be in amps or millijoules.
Check the spark plug wires and the spark plugs.
The EGR valve may be stuck open. It is near the throttle body. It will have a vacuum connection that should allow it to opem amd close when you remove/attach it. If it does not, try cleaning it, but be careful and gentle as the diaphragm may get damaged.
Cechk charging system, for a 12V system it should be between 11 and 15 volts.
Check Mass Air Pressure, or you may have Air Intake Temperature sensor.
Check the timing as a worn out belt or/chain could skip a tooth and cause this issue.
Check the vents on the laternator to make sure they are clear as this will cause it to overheat.
Check camshaft lobes for signs of damage or worn out lobes.
Check batterry cables and make sure they are not corroded and are a tight fit. Check at the battery and where the positive goes to the starter/solenoid and the negative goes to engine block.
Check distributor for wear, loose bearings, etc.
Check computer for good connections and corrosion.
Also check accelerator cable to make sure it is opening the throttle boddy fully.
Let me know how those things check out and we will be here to help walk you through diagnosis further. I wish I had specificatiosn for your vehicle, but it is not listed so I assume it is a european only release.
I will do the best I can and be here to walk you through any process that you have questions about.
Tuesday, October 11th, 2011 AT 6:13 PM