83 cab

Please help diagnose my ignition problem. After buying and driving my father's 83 Cabriolet w/45,000 mi from Ohio to Colorado, the car died in Colo Springs. There in no spark at the coil or plugs. Tested primary coil circuit - 2 different meters read closed circuit = 0.00 ohms. Is this a bad coil or just a reading out of the meter's range? Secondary circuit about 700 ohms. How do I test the CD box? Can hear whining w/ignition on.

Dial 911

Chad,
Zero ohms across the coil primary indicates an open winding; you should see some resistance. The coil may indeed be bad. It could also be intermittent. Inspect the coil for internal oil leakage near the top. If you find oil, the coil may have failed internally.
If the CD box is humming, the box is probably ok.
Also, check the green distributor pick-up wire. It plugs into a socket on the side of the distributor. Make sure it's in there tight. Without this wire, the CD box gets no signal, and no spark is generated.

83 cab

Thanks

There was oil on the top of the coil. I'll have to order and install a new coil and let you know.

83 cab

Well,
After waiting on a new coil (part of the price of living in the mountains) and installing it, there was no change. I have not been able to test the new coil w/multimeters yet. Could it be that the CD box is whining, yet broken. Or could there be a voltage supply problem which would cause the lack of spark? Let me explain the history of this car. This car was purchased by my father in 1986 w/26,000 mi. It was driven occasionaly, but regularly for about 10 years. For the last 4-5 years the cas has sat, garaged, with little or no maintenance or miles (45,000). It has been prone to low water levels in the battery and has been run on several occasions w/ very low water levels- caused eratic tach readings, difficult running, odd electrical problems, blown headlight bulbs, etc untill the battery was replaced (this happened 3 or 4 times). This is where I bought the car (after a 40,000 mile tune up and many other maintenance/repairs) from my father. I drove it for 250 miles around Columbus w/ no problems before driving it 18 hours to Kansas one day and 6 hours to Colo Springs before it died the next day. Could these battery problems have damaged the voltage regulator (where is it?) or alternator or CD box. Any Ideas???

davis911s

Chad these electrical gremlins can really be a pain. Do you have any other Porsche owners in the area? If you do what you can do is swap in a part that is known to be good and see if there is any difference, otherwise you may sppend, spend and spend. Ensure you check to see that there are no wires loose or disconnected, also check all the fuses.

Since the CD is whining it sounds like it is good to me. I had this same problem and it ended up being a disconnected wire in the engine bay, take a real close look.

Good Luck

Shawn
77 Targa

83 cab

Thanks-
I've got all weekend to check things out. I live in a small town w/very, very few P cars. I did find out there is a guy who lived in Germany for 5 years and is a Porsche & Mercedes master tech.

George 86T

One other suggestion I'd make would be to check (polish the ends) of the #@&%^$ Porsche fuses. They're notorious for corroding--and after sitting as long as it has you can rest assured that "ol debil" corrosion has taken some toll! As was said earlier--if you were metering properly, the old coil had an open primary. Even if used on the wrong ohm scale, there would have been at least a needle tic if the primary wasn't open. Good Luck!

Dial 911

Have you checked the distributor signal wire?

83 cab

It seems to be the cdi box. There is an excellent trouble shooting tech section at the permatune web site. Despite the whining noise w/the ignition on, two tests fail- there is 12v to the box. A word of warning- after testing & replacing my old coil based on a test suggested by Haynes I have found out that few mulitmeters under $100.00 can really sense ohm loads that low. I used a $75.00 Craftsman autoranging clamp on digital meter that showed a closed circut across a coil circuit that should have read 0.7 to 0.4 ohms, and all ground circuts suggested by the Permatune site. I feel its highly unlikely that all my grounds have a perfect 0.00 ohm load. Having no handy Fluke retailer locally I can only tenativly blame the multimeter, but the new coil reads the same as the "bad" one. I'll be replacing the cdi soon & let you know.