I put a pretronix ignitor in my 6 recently and my first real drive with it, 45 mins to work on Monday, car ran very well. However a few minutes before getting home the car started to run rough.
The car runs fine for about 15 minutes or so, then it will run rough below about 2200 rpm, kind of like the dwell is off a bit.
Could this be the pretronix?
I used to have a MSD6 in it, and it would over heat in stop and go traffic causing the car to rough very rough, until the MSD cooled down. I wonder if this is a simmilar problem. Monday's drive was not stop and go, and no overheating was happening.