How to test a 6 pin CDI ?

billjam · billjam's Garage

I am trying to track down some electrical gremlins in my '86 930 which has the Bosch 6-pin CDI (same as earier 3.0 litre SC's).
My 930 shop manual has some sketchy instructions for testing an 8-pin unit, but what I really need is a set of test specs for the Bosch 6-pin unit along the lines of the equivalent PermaTune CDI unit below (taken from their website).

T77911S · 01-09-2012, 11:46 AM

if it is randomly cutting off, you need to figure out if it is ignition or fuel. when it is not running, check ignition. keep a spare plug handy to make it quick.
for ignition, usually random dieing is the result of heat and about the only way to fix it is to what for it die completely (sucks) or swap CD, coil and possibly dist. (one at a time)

for fuel, look for fuel pumps, relays and dont forget the speed sensor.
you can go here for my explanation of the fuel circuit

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/615670-fuel-pumps-not-working-ign.html

i hope this helps

pwd72s · 01-09-2012, 12:20 PM

Since it's always good to have a spare CDI unit, why not buy one from a wrecked-em yard?

There are peole here stateside who rebuild them. Maybe somebody in OZ does the same?

Mysterytrain · 01-09-2012, 12:57 PM

Bill,
Check the front fuse panel. I was suffering with the same problem a few years ago and went round and round trying to track it down. I found the long fuse block had broken in half. The break was difficult to see because it was hidden by the fuses. I guess over time the plastic just gives up and can crack and become a source of intermittent electrical problems.

billjam · billjam's Garage

Still looking for test specs. Surely someone knows how to test one of these

HFR_Racer · HFR_Racer's Garage

The Porsche service manuals serve as a good starting point. I also have developed a good CDI / ignition troubleshooting guide fro my '87 930.

Send me an email..

timmy2 · timmy2's Garage

Interesting thread here:
http://forums.pelicanparts.com/porsche-911-technical-forum/203100-6-pin-sc-turbo-cdi-unit-repair-documentation.html

patkeefe · 05:13 AM

Search and use Early_S_Man as a criteria. Warren had lots of stuff on the 3 and 6 pin boxes.

OOPS!
Link above by timmy2 goes right to the thread I was thinking of!

billjam · billjam's Garage

Thanks for the input guys. I now have a heap of stuff to work though on the weekend!

WRGREENER · WRGREENER's Garage

i used SPECIALIZED ECU REPAIR out of Florida they have a core and a 5 yr warranty. They are customer friendly and may educate you on the testing as well as replacement options.