slow cranking power once engine is hot

Not to open a completely new can of worms, but have you bypassed the resistance wire that feeds the coil/pertronix or are you using s relay such as the rocketman, or pertronix ignition feed relay? This could be contributing to your “only happens when hot issue” as well as the failure of your first pertronix unit.

The peretronix requires 12v to properly operate and the factory power wire that feeds your coil is a resistor wire that under a load (hooked up to your coil) supplies much less than that and as it heats up, which it will because it is a VERY thin wire that creates more resistance as more energy hits it due to it being an electrical “choke point”. In essence what you will have is a car that runs great upon initial start up, and the warmer the engine gets,the worse it will run. Will also run great as long as revs are up but at idle will die unless you put it in neutral and keep the revs up. Had it happen on my '68 and after telling these guys what it was doing and my ignition setup they made me awareof the dreaded “resistor wire”. Installed the 12v power relay and those problems are gone.

I only mention this because you stated the problrms arose on a warm engine, and you are on your 2nd pertronix unit with no mention of either bypassing the resistor wire or running a power relay.

So if you aren’t running a relay or haven’t bypassed your resistor wire do so immediately. This would explain a failed unit AND your warm engine issues.

Hi Guitar the reason im on my second pertronic ignitor is because before this problem i had a whole lot of electrical issues one being a faulty ignition switch which was sending a live feed to coil when key was off. This cooked coil and also fryed the ignitor i replaced both items but the coil i got to replace the cooked one im thinking was the wrong one which i suspect was the cause of the of my cranking issue when hot. I have now replaced that coil with a pertronix coil and havnt had the starting issue when hot so far.

I got you. I just figured I would give you a heads up in case you hadn’t done one or the other.