Lifespan of petronix?

[911kiwi]

Hi Guys,

Installed my petronix 5 1/2 years ago - fantastic! Couldn't have been happier - BUT now the 72S has started running rough.

So I did the valves, new plugs, timing. Idles nicely, but once warm & under load it coughs & splutters intermittently. Will drive for a couple of miles then lose power. Occasionally runs on when turned off.

What the .....?

So I'm thinking that the petronix is giving me grief.

Should I change out the plug leads & dist. cap first? (I have new spares on the shelf) Pulling the petronix out & replacing the points is more hassle ...

Anyone had a petronix for more than 6 years?

Your thoughts appreciated

Gary
1972 911S

[azasadny]

Gary,

I would have a spare" Pertronix and swap it in to see if it fixes the problem. As with any electronic device, the Pertronix could be "bad" and the spare is always a good idea.

[ossiblue]

I've not heard of any typical life span for Pertronix, in fact most comments reflect longevity. Are you sure your problem lies there? Could you be having a coil/CDI, or other electronic malfunction instead?

[Early_S_Man]

If you do a search of the archives ... you will find that several Pelicans have had Pertronix failures, and the common knowledge is to carry a spare set of points and the tools to retrofit them ... if you don't want to be stranded in the middle of nowhere!

[Deschodt]

17 seconds on my car... And it was not plugged wrong.
Reverted to points, there is nothing wrong with points anyway... You would think from all pertronix posts that points must be replaced weekly... I still have fingers left to count the number of times I've adjusted them (even less replaced) in 10+ years of VW/356/911/2002 ownership ;-)

[cmcfaul]

Once you get rid of the points you will never go back. Adjusting the dwell, etc on points is the biggest PITA there is. I installed Petronics about 6 years ago and it still has that just adjusted the points feel. Maintenance has be completely zero. Unquestionably the best mod I have ever made to my car.

They use the hall effect that relays on a magnet. The best way to de-magnetize a magnet is with heat. So, it is possible that after time the magnet looses its power and the unit could loose its effectiveness. But mine works perfectly after more then 25k miles.

Chris
73 911e

[304065]

Actually, there are MUCH bigger PITAs in the world of Porsche.

And for a post-1969 car with Bosch CDI, there's only about 420mA of current flowing through the points, so Porsche eliminated the condenser entirely from the distributor. The capacitor in the box charges so fast that "Dwell," which is so important in Kettering ignition, isn't very important with CDI+points.

Here's the trouble with Pertronix or an optical-trigger ignition like the Crane: when it fails, you can't tell. When it fails intermittently, you can't tell. Points are easy enough to diagnose. Replacement? Remove screw, install new set, snug screw, set gap, apply clamp load to screw, connect faston to terminal. SWB points are only slightly more difficult and easier if you pop the distributor out, a two minute task.

I would MUCH rather be stranded at roadside with ignition problems using points than any kind of hall-trigger. I admit that the hall-trigger is more accurate in combination with EFI, as in the case of Motronic. But when the position sensor fails? How do you tell? JMHO.

[safe]

I bought the Ignitor II together with the Flame-Thrower II Coil earlier this year but it is still on the shelf.

You are supposed to have the Ignitor II to be able to use the lower resistance Flame-Thrower coil.
But when thinking about it, what the h*ll does the ignitor has to do with what coil you can use? It's the CDI that powers the coil, or am I not thinking straight?

[azasadny]

I've always used the Bosch blue coil and I've used PermaTune and Bosch CD units as well as Pertronix and points. Tab Tanner converted my car to Webers last December and put the points on and I use the Bosch CD unit and Bosch blue coil and the car runs great. I'm sticking with the "old school" solution, no more PermaTune, Pertronix or aftermarket coils for me...

[RoninLB]

Originally Posted by safe

, what the h*ll does the ignitor has to do with what coil you can use? It's the CDI that powers the coil, or am I not thinking straight?

you're straight

[RoninLB]

Originally Posted by john_cramer

Actually, there are MUCH bigger PITAs in the world of Porsche.

Here's the trouble with Pertronix or ..........:

. But when the position sensor fails? How do you tell? JMHO.

carry a test light


also, everything electrical will eventually fail.. that includes points

[911kiwi]

Thanks for the replies, guys - I DO carry a spare set of points just in case (as suggested by numerous posts!)

But as John mentioned - how do you know if the petronix fails? Points tell a story.

Looks like it's back to points for now & maybe buy another petronix later if the retrofit solves the problem.

Cheers

[RoninLB]

if you confirm you have 12v feeding the Pertronix and still want to test module

[304065]

Ron, baby, I carry a portable oscilloscope 'cuz that's just how I roll. . .

[Joe Bob]

they usually go all at once......not intermittently. I would suspect something else.

[RoninLB]

connector block makes flipping a Pertronix painless.

[safe]

Ronin:
So this (PP catalog) is just BS, at least with a CDI?

The Ignitor II has many of the same features as the Ignitor, but it's smarter. The Ignitor II units sense the coil current level and use a powerful micro controller to adjust the dwell. Variable dwell helps to maintain peak energy throughout the entire RPM range.
Ignitor II systems develop up to 4x more energy between 3000-5000 RPM compared to standard ignition systems. High RPM performance is improved when using the Flame-Thrower II super low resistance (0.6 ohms) 45,000 volt coil.

[azasadny]

Ronin,
Thanks for the pictures, they're clear and very useful!

[RoninLB]

Originally Posted by safe

Ronin:
So this (PP catalog) is just BS, at least with a CDI?

I see ignition through my own lens so i may be prejudiced. The PP comment came from the Pertronix web site.

- combustion ignition voltage demands only what's necessary no matter what the coil is claimed to output.
- The MSD works for me and carbs. MSD will also cover up some idle and start deficiencies of a beat engine w/ bad rings, valves etc.
- if running stock Bosch ignition w/ stock CIS, MSD will probably not contribute anything.
- imo the best coil for Bosch CD is the old black and expensive Bosch coil. I have an old one in my garage and maybe part number is on it ?
- I use Pertronix 1867 Ignitor to replace points. I have a spare 1867 wired and ready to be screwed into the connector block.
- if moving the Ignitor within the dizzy the ignition timing is affected.
- I use blue loctite to fasten the Ignitor.
- imo all electronics is heat sensitive. Even Ignitor instruction say the Ignitor will be damaged if ignition is left "on" without engine running.
- I've been running the 1867 for 20,000 miles problem free. Even hung around 100-110F deserts with only slow street driving with no problems.
- I rewired whole ignition wiring w/ Ancor marine wire that has tinned copper strands.
- imo, poor wiring connectors or even faston connectors and old stock wiring is a problem waiting to happen.
- Waytek www.waytekwire.com has double wall shrink tube, "Polyolefin Dual Wall", that looks almost stock to encase wire completely.

different strokes for different folks

[911kiwi]

Wow, thanks Ronin - that diagram & instructions are great!

I'll go out & test the unit now & hopefully not have to pull it out. There's definitely 12v going to the unit so no "low voltage" issue.

Fingers crossed.