Pertronix
 

On a very busy highway our 75 backfired stopped running.
I have always been a supporter of the pertronix ignition but it failed.
Luckily I had a set of points (in the pertronix box) and was able to remove the distributor and install them using the cars tool kit.
They did last about 10 years but, they failed.
If you have them in your 911, carry a set of points. A wiring diagram and distributor removal tools. Getting the nut off with the tool kit wrench is challeging.
I am going back to points.

Thanks - That's a good reminder. Mine has been running with Pertronix for about 12 years...

Pertronix is a Hall Effect Sender which doesn’t like heat. When things get toasty, it’ll stop working … and come back when temps drop again.

Pertronix
 

The heat may have contributed to the failure as we were in slow traffic for 45 minutes and it was very hot. However the oil temp was at 180 which should be fine in the compartment.
I opened the sensor up with a vise and found a transistor that was connected to the base of the device at one end with screw and at the flat spot it looked liked some type of glue or substance between the back of the transistor and the base. The heat must expand the materials at different rates and cause them to separate and fail.

Not designed for the air cooled engines I suppose.

we have them in a 72 but I ordered new points from Pelican and will remove them.

Makes me wonder about other aftermarket devices like the MSD's. Can they handle the heat in the engine compartment?

I've had the Pertronix in my 75 for 17 years and thankfully it hasn't failed on me yet - I live in CA also and have been stuck in freeway traffic in 100+ deg F temps with oil temp at 195+ deg F several times with no failures. Your idea of carrying a spare set of points is a good one, thanks.

Oops, sorry. You're not in CA.

Pertronix
 

I don’t think the sensors fail mechanically, rather electrically. They typically don’t like to go above 90 degrees C.

As they need 12V and a solid ground, assume the 12V supply is solid as is the ground. Not a bad idea to run a seperate ground from the distributor body to the earth point on the body as earthing via the engine case is not ideal .. the distributor is driven by a brass gear for one.

Just my $.02......had pertronix for over 12 years. Once They were set up correctly, never had a problem.

I love Pertronix

I've used Pertronix in a half dozen old cars. No problems (yet).

I was a pertronix advocate. Mine failed. I tossed 2 ssts in the garbage. If you are lucky they wont fail on a high speed narrow highway in a desolate area, just giving my experience which was very disconcerting

Your thoughts on points would be valid if points did not fail. Problem is they failed at such high rates that they created a market for Pertronix. Any component can fail, having spares (like you did with points is a good idea. Could have just as easily lost the rotor, fuel pump, coil etc.

john

Yes, but a simple fix is to just clean the points, no need for replacement.