CDI/Ignition Help

[tfulmer1]

Hello all,



I listened for the whining sound at the CDI, however, there was none. I read at www.permatune.com (this is the unit that is there) that they do not whine.

I had no spark at the plug..dist...etc...

The harness going to the CDI had a voltage of 7.5V. The car had 12V at the battery. (this seems like a problem but not sure)

Anyways, I disconnected the tach plug by the o2 sensor....AND IT STARTED! plugged it back....and no start. (The tach is somehow part of the circuit I believe)

THIS is the problem, but I am not sure from here. Is this a problem with the Tachometer itself or the wire leaving the distributor to the CDI? The car will run now but I have no tach. Is it a possible ground problem.

If anyone has been there...done that... please let me know. I did not see anything with my search.

Thanks.

PS car is an 89 930 but I believe the SC 911s had the same set up...plus I hope you guys know more about maintaince than the 930 guys.

[SteveCarr]

Search on here there is a lot of info about the 6 pin CDI on the 930. In your case I guess that you have a fault with the tacho that is grounding the pulses used to fire the thyristor in the CDI unit.

Regards

Steve

[Gunter]

I believe that the turbos had an 8-pin Bosch CDI module at some point?
Permatune doesn't have a good reputation for performance or durability, do a search here.
Why not try and find a used 6 or 8-pin Bosch?
Or replace the Permatune with MSD?

[SteveCarr]

I have an 1985 930 and mine has a 6 pin unit - I have it on the bench right now.

Regards

Steve

[Gunter]

That would be even better.
A 6-pin is easier to find.
I wonder if the 8-pin module came in after '89?
Hmm............

Lot's of stuff here:

6-pin SC/Turbo CDI unit repair documentation