Porsche Repair: 1976 Porsche 911 s - Points Problems, porsche mechanic, porsche repair

Question
The points in my 911s don't stay in adjustment. The car is a one owner and has been in my family since new. It has always been well maintained and has no problems to speak of. The car is stored from 11/1 until 3/1 or 4/1 every year. Late last year it began to develop an intermittant "cut out" problem, where the tach would go to 0 and hesitate for a few seconds. Very intermittant at first and then to the point I couldn't drive it. The local Porsche repair shop said the points were very bad - pitted I think they said, and they replaced them. Worked well to end of last year, and the first 1000 miles or so this year and then same thing. took it back and they adjusted the points, they weren't staying adjusted. Ran great, as usual, for about 200 miles and they went again. Had it towed to the repair shop and points were replaced incase there was something wrong with the other set and readjusted. This time didn't get home and it died. The Porsche mechanic, who is good and prepaires a lot of racing Porsche's can't figure it out. Any help?

Answer
Hi John Paul.

This is an easy one.  The condenser is worn out.  It's the small (1" to 1 1/2" long and about 1/2' to 5/8' in diameter) cylindrical component usually attached to the distributor.  One wire leads from the condenser and enters the distributor through an insulated opening.  The following description, by whom I don't know so as to properly attribute it, is one of the best I've seen telling what the condenser does:  

"The condenser is present to absorb the 'spike' or 'pulse' that occurs when the points open (and the coil fires). This is because current is flowing when the points are closed, and while the coil is 'saturating'. When the points open, the current is still trying to flow. The condenser trys to absorb this.  'Point-degradation' (material transfer from one contact to the other) occurs for both 'over' capacity, and 'under' capacity condensers. The pitting and 'tit' formation that occurs at the points is a result of 'over', or 'under' capacity.  'Over' capacity results in the 'tit' pointing in the 'plus' direction. And, 'under' capacity leads to the 'tit' pointing in the 'negative' direction. Ideally, condenser capacity would be selected so that there is no tit pointing in either direction, and all that is seen at the points is a 'burning' that erodes the contacts away, from both surfaces, equally. Indeed, this is the result that is most often seen on well-used points.

The value for condenser capacity is not cast in stone. It can be different for different people, depending on how they use their engine. And, not all condensers are made with precision. They vary from unit-to-unit. So, when you buy a new condenser, it is not necessarily going to be exactly the same as the last one. I have occassionally seen condensers fail. So, I usually replace them.  I HAVE experienced a condenser failure on my own car. The symptoms were, at first, intermittent 'sputtering', or misfires. As it progressed, it got to the condition where the vehicle did not want to run at all. It would start and immediately die."

Gosh...sounds like your little family jewel, doesn't it.  I'd like to suggest a permanent fix to the points-eroding problem.  I'd take this opportunity to install a "pointless" ignition system.  You or your mechanic will never have to replace the points or condenser and the points will never need adjusting again.  Sounds too good to be true?  I have a Crane set-up on one of my cars and it is well worth the money.

If you'd like to consider this idea, here are a couple websites to begin your research:


Pelican Parts in California...read the descriptions for the Crane/Allison products as well as the Ignitor (by Pertronics) products.
http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_igniti_pg3.htm

Other Retailers of Pertonix...just tried to find a better price than Pelican...not yet though:
http://www.classicgarage.com/classicgarage/229.html

http://www.vintageperformance.com/retrorockets/porsche.htm

I've found Pelican to be an excellent source of Porsche parts...and close to or better priced every time.


If you want to be faithful to the original Porsche design I'd re-read the quote above, replace the points and condenser (again) and check very often for the degradation described above.  If your condenser is compatible with your car, there should be very little noticeable pitting.

One last thought, while doing a bit of research I did find comments that suggested if you have an electronically activated tach, there are some additional considerations...I'd check into this and see if there is a "workaround" or an "adapter" provided by the manufacturer.

Good luck with your little treasure.

Dave