CDS Unit Failure
 

I've got a quick question ? After spending a few days trying to figure out why my 1979 911sc would not start.... I took it to a shop.... they've diagnosed the problem as a failed CDS unit... quoted about $1700 for a replacement....

My question is - when I was looking, the unit put out the "squeal" that signifies operation - can the unit still fail and put out the noise.....?

Do a search here, this topic is EXTENSIVELY covered. Search under CDI box (they don't call it BHKZ anymore), a bunch of guys had the same problem.

I don't know the procedure as I have an MSD 6AL which is a heck of a lot cheaper than $1700.

Good luck!

Thanks....I did the search but could not find anything on the noise+failure issue....

I've personally never heard of a CD box dying but still whining.
Sounds like it could be a dead coil?
Always start with the cheapest fix. On top of that, if the box is dead, you can have it rebuilt for about $300. Screw buying a new $1700 Bosch unit. Nobody does that!

Leland is correct. If the CDI buzzes, that indicates that it's probably O.K.
Call Tom at Pelican Parts. He can probably advise you about a Bosch rebuilt,
if you really need another CDI.

Proper diagnostics are always a good idea especially when there're costly
parts involved. The green pickup wire from the dist. may be your problem.

$1700! So they come in gold with diamond insets. I think $omeone'$ trying to $lide one pa$t you for fun and profit. My Bosch is still going strong and it's in all likelihood the original one, given how long I've owned the car. The Permatune internal coil I bought (so I could go faster) lasted six months. If you truly need one, which seems unlikely, rebuild the Bosch, as suggested. Wiggle some wires first.

$1700 is how much they cost, new. But no one I've ever known has actually SPENT $ 1 7 0 0 on a CD box. You can buy a used one, have your rebuilt, or go with a Permatune or MSD box for a fraction of the price.

http://www.ottosvenice.com/ Is very reputable and can rebuild a CD box.

I'd check the coil and the generator pick-up coax wire (green wire from the dist. to the CD box).

Best of luck,

How's your coil?

They're going to tinker with it for a couple of days to make sure of the problem..... Thanks for all the imput... this is a great forum for those of us who are new the the fast lane........

I hope your not paying them to learn on your car...
Post your location...there may be someone nearby with a clue

Ouch, you're right. The '99 Perf. Prod. catalog has them at $1199, expensive even back then. I still don't trust the Permatune, although I understand some folks have run them successfully.