Porsche distributor pertronix mag signal How to diagnose?

[micotito]

I have this 3.2 liter 1979 Porsche, distributor with pertronix ignitor II pickup, MSD 6AL.

Car starts fine and keep ralenti but spark is jumping all around confirmed with a timing light. Trying to accelerate cause bad misfire and backfires.

Attached is MSQ file and csv log.

Any ideas on what could be causing this.? Noise, bad pickup.?

Thanks

[ihateforums]

I am guessing your distributor is similar to the Bosch one that I used to have on my 320i, with centrifugal and vacuum advance. After many years and miles the mechanism wears out and the spark timing becomes sloppy indeed.

Does your setup use the distributor for ignition timing, or do you control it with MS instead?

[micotito]

Yes, but vacuum mechanism is now welded so MS take control over spark timing. I got pertronix pickup wired to pin 24 jumped to XG1.

Not confirmed but seem that pertronix ignitor II is a smart dwell control and appears that is changing pulses by it's own.