We've done a compression test and its down on all 4 cylinders. The car was taken out today and given a drive 'round at 60-70mph for about 15-20 minutes. The misfire is still there, and it's the third cylinder (third from the left from driver view perspective.)
We've tried the spark plugs, HT leads, distributor cap etc... Its not any of them.
Anybody have any other ideas.

Thanks.