Cheap distributor cap failure - lesson learned.
 

So a year and a half ago I fitted a very cheap distributor cap on my na, today she would not start.

Removed the cap and found as the picture cracked.

Oem bosch from now on.http://forums.pelicanparts.com/uploa...1429290623.jpg

What brand failed?
 

What brand is that failed cap? It has the black outer shell similar to a Bosch, it's not just a re-branded Bosch? Is that an actual crack or a carbon track?

Not sure on the brand but the part number on the side of it is:
ARBP314101

it's also dated 2012/06/07

It is cracked down either side of the coil pin and all the way out to one of the plug contacts.

I was a bit wary of the quality of it when I fitted it as it always seemed a bit loose compared to the bosch one it replaced.

I have a used bosch one in temporarily until the new one arrives.

Interestingly the used bosch one does not have the black cover.

Cheap distributor cap failure - lesson learned.
 

Last year I found that only a Bosch would successfully attach on my 83NA. Tried a Beru and the bottom latch wouldn't.

I was told the cheap ones are made in the Bosch factory. Can't be many people interested in making 944 caps. Also, Bosch isn't the same it use to be. Look at the junk they make for the air cooled market now.

Bosch one arrived today and while they look the same they are clearly different, the bosch one is way heavier for a start.

Also it is a lot tighter fit.

PA_944:

Bosch parts is all I ever have used in my Porsche cars. You're correct, the Bosch 944 distributor cap is a lot heavier and lasts much longer then the cheap parts produced.

It does have a tighter fit which makes for a better seal.

Good luck.

i can vouch that not all caps are created equally. i swapped a newer used cap i had onto my 85.1 after i installed the new belts along with a shiny new blue anodized PCG cam gear. when i started the car up it was a horrible grinding sound. the hooks from the aftermarket cap were scraping the inner rim of the gear. after pulling the cap and trying to clearance the hooks unsuccessfully I just gave up, cleaned up the mess and installed the old cap back on. it was an OEM cap, just older. more importantly, it fit