How to test power to the coil

[Sam83]

1983 Porsche 911/930 3.3L Turbo

Hi,

Crank no start

I'm not sure if I am getting power to my coil.

Any one wish to help?

Thanks

[908/930]

Do you get a high pitched sound from your CDI box with ignition on? Is it the original CDI? This system is a little harder to test, the CDI gives a short pulse of high voltage to the coil when triggered. Search test 6 pin CDI, and that could help.

[Alan L]

The other thing to do is pull some plugs, for easy cranking and see if you are getting spark at one (#4 would be easiest).
Alan

[930Paddy]

I had a similar issue before and it was the cdi, as far as i remember it was still making the high pitched whine but not making any spark, i just pulled a lead and put an old plug on it to check. What made me think the cdi was the culprit was my tach bounced before it died and i remember reading on here that that was a tell tale of cdi failure. There is a way to test your coil with a resistance check but i forget the numbers you neeed to see if its good, it was on here somewhere from doing a search that enlightnened me at the time.

[Alan L]

A bit of a search should pull up those resistance numbers - I think I have seen a list for the various coils.
But first I would just crank and verify no spark. Then you need to isolate - green wire, CDI, coil.
Alan

[stre]

Check for 12V at the coil with the ignition in the on position. If there’s no power, trace back to the ignition switch and fuse panel. Also check the CDI box (common failure point) and make sure it's humming when keyed on.