I agree with euro 287
get the scope done or at least a wet/dry compression test and give us the results. If the test comes up with one or more cylinders very low on the dry test then the wet test they look much better you have bad piston rings. If they are good through out we will start looking at fuel and ignition problems. How many miles are on the car ? What is some of the past work you have had done ? Any engine work ?