pertronix ii

It might if it's the wrong coil for the unit. There are three types of coils I've seen listed, one is for points, another for both points and electronic and a third for electronic only. I ran the wrong coil with a Duraspark and it gave me fits.
 
I love mine...I've got the pecrtonix II in my 68 with teh igintor coil. really a nice set up. i guess i never drove mine with points, so i can't say what kind of a effect it had on it, but from what i hear, it sure beats points. :D
 
Although I don't have a ton of miles on mine (yet) it starts very quickly, runs great and even though it's over-carbed, the plugs look perfect, light tan and dry. I suspect most of the people who had problems either have a bad ground or didn't bypass the pink wire. I've even left my key on overnite (twice) while working on the car, and it fired right up after I charged the battery.
 
What's the latest word on Pertronix II's reliability? Thinking of taking out my non-vacuumed billet distributor for a stock one that's converted with the Pertronix to get some street manners back.

I've put about 23k miles on two different Pertronix setups and they both have treated me great with nary a hiccup. Mine tends to run on the uncomfortably warm side here in summer and it hasn't given me any fits yet (8500 miles on this unit). Seemed to give a nice bump in the midrange in my '68 after I ditched the points, too (had about 15 k on this one). I wouldn't even bother going without it anymore.

I don't know that the coil is the cause, but as others have said it could be. Pertronix Flamethrower coils (also have had these with both Ignitors) have been similarly reliable and of course put out a good strong spark.