Not sure about the newer potted permatunes, but the older ones used a 100 ohm resistor in the trigger circuit which is a little on the high side for keeping the points clean. Probably not a bad idea to clean them once a year as general maintenance if using the permatune. Fred

side note, or question..

car had plug wires with grounds. is it ok to switch to the non grounded wires? aka magnacore

also it has a bosch rotor, i think i ordered the the porsche oem one.

I did a little more research after our conversation.

I found Peter Zimmerman noted this in an old thread "Yep, the grounded shields on CIS cars were to divert any stray sparks from plug wires to ground, rather than have those sparks travel to the plenum chamber of the airbox."

Reading on, this didn't help the airbox from exploding, so the grounded/shielded wires were done away with after 83.

In other words, you should be fine to use magnecore non shielded, non grounded wires. However and from my understanding, the solid core magnecore wires are for use on MSD ignition systems.

I should also note they look totally rad, that's why I run them! :-)

As for your rotor, aren't the Porsche OEM parts made by Bosch?

thank you!

I run the clewett wires and love em. Cleaned up my ignition and they look great too. (ie not red)

Yo red ign wires look like they belong on a v8. Especially half dirty loose ones just hanging there like spaghetti.

and im back :mad::mad:

put everything back and no start again.

borrowed a new cdi box from a member... thank you

new cap and rotor and wires..

cdi box has the hum like it should.

with key on i get NOTHING to the dizzy or coil.. also when i move the points i get nothing at all SmileWavy

im lost

checked all grounds?

it runs!!!!!


reading this ....http://forums.pelicanparts.com/porsche-911-technical-forum/905258-75-no-spark-no-power-coil-2.html

the interior gound wire going to the cdi was the issue. fired right up like weekend and bernies.

going to test the permatune now.

old box works... idles fine but rough. the yellow light on the permatune has a flash every here and there

Wiring diagram for 3-pin
 

Thanks everyone for all the help. One addition I wanted to make was how to wire the CDI unit in. Like many of you, I was dealing with an old and brittle harness. What I thought was a CDI unit issue, was in fact a shorting issue in the harness. Many hours with my ammeter trying to figure it all out is what that cost me (oh yeah and needlessly buying a new Permatune unit $$$$$). Since you've all helped me, I wanted to share how to simply wire the CDI unit into you car, if like me you decide to start a new.

https://static.wixstatic.com/media/9...I%20Wiring.png

Good luck all.