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Hi everyone,

I think I need help again.

Last year a friend and I overhauled the engine and among other things changed the old Duraspark Ignition to a Pertronix 3 ready-to-run Distributor.

At the time there was only the ignitor 2 coil available (thanks COVID), so I bought and installed it. The engine started fine and since this June it ran with no issues.

In June it started hardly and ran really bad at idle. In the first troubleshooting I found out it had a real weak spark.

Next time it wouldn't start at all, no spark. So I figured: Must be the coil, since I bought the wrong one in the first place.

From here on I started to chase my tail on and off the last 4 month.

- Changed coil 2 times

- bought and installed new battery

- checked if the rotor was even spinning and in the right position

- checked wiring and ground

- measured everything including the signal of the ignition with an oscilloscope (another friend of mine who is a car electrician did it) The only interesting result was there were only 9V at the coil during start. So we installed a cable from the battery directly to the coil and had perfect 12V (disconnected the original power supply of course and even the tach)--> still no spark

- finally I tried if there was a spark from the coil to the distributor and I couldn't believe it: with the direct connection to the battery the spark was so strong you could have welded with it.

- So I figured if everything works up to the distributor, the Ignitor 3 module must have gone bad. Ordered a new one and installed it last saturday and guess what: no f***ing spark...

I was so frustrated I had to close the garage door and walk away to avoid solving the problem with a hammer.

Now a week later I still have no clue what to do next.

If anybody has a good idea and can point me in the right direction I would really appreciate it.

As always. sorry for my bad english!

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After additional countless hours of troubleshooting including:

- again checking everything a dozen times

- new wires,

- electronic module,

-direct 12v wiring and ground from battery,

- new cap and rotor

- and much more

I decided to remove the Pertronix distributor and switched to a used Mallory distributor that came out of a running Pantera (car is getting restored at the moment).

What can I say: Car started right up and runs like nothing has happened. I think you can imagine my face at that moment

I disassembled the Pertronix Distributor and couldn't find anything wrong, I even gave it to an retired electrician that worked in BMW development and is one of the smartest guys I know and he also couldn't find anything.

Fun fact on the side: The Tach that always read slightly wrong with the pertronix is on point now.

@rocky posted:

My guess is it was Item #4 (Power Feed & ground).


it didn't work with the original wiring and also didn't with clear 12v from battery to coil and a new wire from coil to ignitor module (tried 2 ignitor modules with different wiring) and direct ground from distributor to battery.

Don't get me wrong, it is possible that you are correct anyway but I sure as ... don't know what else I could have tried.

Last edited by GeorgS

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