'83 911SC electrical - coil question

[ericinboca]

1983 911 SC won't start. We don't get a spark - either out of the wires from the distributor cap, or straight out of the coil. We swapped out the coil twice with two new ones, and still don't get a spark either way.

We have power to the coil - BUT - how much power should be getting to the coil?? Maybe there is indequate voltage getting there for the coil to do its thing.

[wvicary]

The CDI module has most likely failed, it's often a leaking or overheated ignition coil that damages the module. With the ignition key on you should be able to hear the module making a very high pitched noise. It's located in the engine bay on the left side near the hinge area for the engine cover.

Edited January 24, 2009 by wvicary

[ericinboca]

Thanks wvicary.

Is there a way to test it? Or does no noise mean it is the culprit?

Looks like rebuilt ones with a core exchanges is almost $300.

[magcuda]

here is test plan, I know it is for a 930 but basically the same systems.

$300 for a CD box? sounds like a permatune, better buy 2 unless the quality has gotten better

930_Test_Plan.pdf

[ericinboca]

thanks

this is a great document

and, yes, the $300 price was a permatune

also found a place that rebuilds bosch CDIs

[ericinboca]

We went through the diagnostic yesterday. Someone along the way in the life of this 911 has made some electrical changes, so I don't have a definitive answer. But we heard nothing out of the CDI module and did determine there is power to it. It goes for a bench test this week, and a likely rebuild. (We found a guy in FTL, FL that says he can rebuild for $220 with a 5 year warranty. Intersting -- we will see.)

[ericinboca]

Fixed - it was the CDI.

Thanks for the tip and for the diagnostic. It fired up the first time after install.

We took the module to ecudoctors.com

He repaired it for $220 and gave us a 5 year warranty.

We will see how it goes.

[wvicary]

Glad you have it sorted and thanks for posting back.