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Pertronix III problems

Posted By: RealWing

Pertronix III problems - 09/07/19 02:05 AM

Installed an Ignitor III (p/n 71385) and 0.32 Ohms coil (p/n 44011) on my Superbird 440-6 dual point distributor. This unit is specifically made for the Prestolite DP distributors and triggers off of the stock cam lobes. Seemed like a good design with multi spark and rev limiter.
However I encountered a random misfire when starting and when engine was running. It was especially bad on a hot restart. The ignition would randomly fire well before TDC and completely stall the engine while starting!!!! Inspection of the unit showed that the rotating plate (holding the module) was loose. The plate could be moved up and down enough that the module could pivot up and touch the cam lobes in the worst case.
Found excessive clearance at the 3 plastic clips under the plate - the original points plate rotated on a ball bearing!!!. From an engineering perspective, the design/manufacture tolerances are far too large.
​We reinstalled the original dual points and the engine starts and runs fine!!!
Pertronix said they will take it back and check it and send a new one - but that is useless because another one will have the same design issues.I bought it on Amazon.ca but they have a 21 day return policy. Took longer than that to determine what was going on. $$$ down the drain.
The unit is completely unusable for this application - BEWARE
Jim

Attached picture Ignitor III_1280x922.jpg
Attached picture IMG_5386_1280x960.JPG
Posted By: Alaskan_TA

Re: Pertronix III problems - 09/07/19 02:36 AM

Mine failed, but I already said that in the thread at www.dodgecharger.com/forum/index.php/topic,136024.0.html
Posted By: moparx

Re: Pertronix III problems - 09/07/19 02:36 PM

this is just the duel point prestolite kit, correct ?
other protronix kits ok then ?
got a buddy that has two kits installed that replaced single point setups in original distributors that are years old, and both work flawlessly.
seeing what was wrong, could a guy get rid of the excess clearance to make this work as intended, or are there other issues ?
it kind of irritates a guy when you spend your hard earned bucks on something, only having to modify it to get it to work.
i have modified countless aftermarket items over my lifetime to get them to be a "bolt on" part. glad i'm not afraid to hack stuff up.
paying the bucks some of this stuff sells for, however, you shouldn't have to be part of the manufactures unpaid "R&D team".
beer
Posted By: RealWing

Re: Pertronix III problems - 09/07/19 04:01 PM

These problems are only related to the Prestolite kit. I cant comment on other Pertronix products. If you Google "pertronix failures" , you can draw your own conclusions.

From an engineering perspective - I believe the random misfire is due to 2 design issues.
1. The module triggers off of the stock lobes for the points. As you probably know, these stock lobes are a rounded profile and make it very difficult to get a consistent clean trigger signal. (ie this kit does not have a separate trigger wheel with sharp trigger edges).
2. The gap between the lobes and module keeps changing because of the loose clearances in the plastic "bearing". As the vacuum advance module pulls on the module plate, it also changes this gap.
I dont see any way to make this work. Simply too many design issues to sort out.
Posted By: moparx

Re: Pertronix III problems - 09/07/19 04:13 PM

good to know. thank you. bow
beer
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