no spark

[chadwallen]

I recently bought a 1983 911 Cab w/45,000 miles from my father. The car sat unused/unmaintained for the last 5 years. After a 40,000 mile tune up and other repairs/maintenance I drove the car 250, trouble free, miles around Columbus, OH before starting back for Gunnison, CO. I drove nearly 900 miles the first day to Kansas. After 6 more hours the next day (100+ degree heat, stop-n-go traffic, very high, but not "red" oil temps) the car died. The first sign was slight missing while goosing the gas up a hill, then complete silence. The engine, distributer turn, CD box whines. NO SPARK. Coil tested bad, replaced w/new (slightly different looking) Bosch. NO SPARK from coil, or plugs. All obvious grounds look good- very clean car/engine compartment. Can I test the CD box? Could it be a bad voltage supply?

Please Help

[fred hannah]

take it back to the crook that sold it to you and have him deal with it.JUST KIDDING OF COURSE. hope you get it runnig. keep us posted.

[Ted Stringer]

Check the grounds on everything. I know it sounds like a broken record, but bad grounds are a huge source of electricial problems. Also check the fuses, replace if they look very old.

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Ted Stringer
nuke3@juno.com
'84 911 Targa aka pocketrocket

[needlevalve]

Might also be prudent to check that your points are clean and operational. I recently worked out the same problem with a 69 that wouldn't spark at the coil or plugs. Turned out to be corrosion on the points contacts that was preventing the circuit.

Regards

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Matt Macpherson
1975 911 S
nvalve@yahoo.com

[twin plugged targa]

Sounds like you need the brains of Warren/Rolund/Jonnie Walkers, etc on this one!.
My ingnition syst. is very different so I cannot help you, but the only advise would be to patiently (good advise from someone that has none)
.... check each system from start to finish, ignore nothing - including that coil you replaced!.
If the car had been standing, what condition was the battery?, spark plugs? etc.
Points are quite often bad on cars left in storage.
I am sure it is something simple as long as you did not cook the engine!.
Exactly how high did the temp needle go?.

Best advice I would like to pass on would be to not giveit to a mechanic unless it is someone you can really trust (I just got stiffed)
rgds Ben

[chadwallen]

Thanks for all the advice, I'll use it this weekend and keep troubleshooting. All plugs are new, cap & rotor too. The temp never hit the "red" on the guage. I was still a couple mm from the danger zone.

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[Ted Stringer]

Do the '83s have points? I thought that was done away with on the SCs.

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Ted Stringer
nuke3@juno.com
'84 911 Targa aka pocketrocket

[Early_S_Man]

Chad,

Was the replacement coil a Bosch 0.221.121.001? The part number is stamped on the bottom of Bosch coils.

Your problem could be the green cable (which is like a microphone cable, with two signal conductors and an outside braided shield) from distributor to CDI-unit, or corrosion on several connectors, both power and grounds, around the engine compartment, including the six-pin connector at the CDI-unit, and all of the connections at the coil.

Your best bet would be to get an Electrifix brush set, and attack the engine electrics with some isopropyl alcohol and compressed air. Clean every connector and ground you can find.

Please refer to this diagram:

http://www.pelicanparts.com/911/911_Parts/Electrical/911_electrical_82SC_Part1-2.jpg

The only way I can think of to test the CDI-unit/coil/distributor would be, after doing the connections cleanup above, turn over the engine to TDC #1, pull out the distributor. Fabricate a six-conductor 'Extension Cord' for the CDI-unit with six male 1/4" quick-disconnects, and six female ... and bring out all six leads to an insulated terminal block, where they can be probed with multimeter and oscilloscope.

In particular, you want to check to see if there is at least 11 Volts available at the CDI-unit. Wheb you spin the drive gear of the distributor, there dhould be a very low-level AC Voltage present at the two trigger leads from the magnetic pickup in the distributor (green cable) ... readable with an AC Voltmeter or oscilloscpe. There should also be 460 Volt pulses at terminal 'A' of the CDI-unit and coil, corresponding to each trigger pulse generated by the distributor.

There are some troubleshooting tips at this page:

http://www.perma-tune.com/Tech_Support/Porsche/911SC.htm

Good luck!

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Warren Hall
1973 911S Targa

[jlex]

I'll bet what you'll find is that your alternator pooped out along the way, and has failed to charge your battery. The battery carried you a while longer until it was completely exhausted, and now you have no spark. Borrow a battery & see if it makes the car go. IF it does, then check the alternator to make sure its charging. Good luck
regards,
jlex.

[chadwallen]

Thanks again for all the help, I'm sure something will result from all the ideas I'm getting. The alternator/battery are good, the car has never hesitated to turn the engine over, just no ignition. I'm curious if an '83 has points, seems there should be an electronic ignition by then. I don't know too much about points- I quickly ripped them off my '74 Bronco and replaced with a MSD system. Should my CD box be damaged, should it be replaced with a rebuild Bosch or a Permatune. I do want to keep this thing as close to stock as possible. My Bronco is my "project" vehicle. Fuses and grounds sound like good (cheap) fixes- I'll check those first.

[Doug Zielke]

NO points in an '83 3.0L

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'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
The Blue Bomber's Website

[chadwallen]

This has only become more frusterating. My multimeter's "resolution" for the ohms setting is 1 ohm (I finally got around to reading the instructions- always a good idea). All tests that are close to 0 ohms read as a closed circuit. Both my new and old coil show a closed circuit across the terminals that should read .4 to .7 ohms. Are both coils still good? All ground tests read 0.00 or closed too. Worse yet, no store in my little mountain town have a meter that seem to be sensitive enough to read less than 1 ohm. Please give advice what brand/models of meters I should shop for. I've been cleaning all the connections I have touched, including engine harness plug, CDI 6-pin, distributer sending wire (female side only- haven't pulled the distributer), all fuse holders- replaced almost all fuses w/new, cleaned relay posts/recepticals, swapped relays from good circuits (power windows, horn) to questionable circuits, installed new fuel pump relay. Would the (I think its a...) oil cooling fan plug (right in front of the battery, next to headlight washer pump?) cause a problem- it seems to have had battery acid slightly melt the fittings.

Regarding the tests I can take: distributer signal lead 599 ohms- OK, ground wires @ CDI harness to mounting flange : 0.00 ohms- probably slightly off, Pin 1 to Pin 4 reads open- cant get ohms reading- bad CDI??, Pin 2 to Pin 5 open too- bad CDI?? Can't take Pin 1 to Pin 5 DCA- meters won't range to this level (200u only). If it is a bad CDI could it have been damaged- and more importantly be damaged again by a bad voltage regulator/alternator. This car has been run several times with low water levels in the battery which has caused erratic tach readings, hard running, no power antenna, no radio, etc, etc untill replaced. Could this have damaged the voltage regulator which, in turn, has damaged the CDI/Coils??

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Chad Allen
'83 911 Cabriolet
'74 Bronco

[Early_S_Man]

Chad,

You may have to head East to a town large enough, but Sears was still carrying some of the lower-cost Fluke multimeters the last time I was there. I believe any of the '70' series would serve you well ... Fluke Model 72, 75, 77, etc.

I don't believe low battery/system Voltage would hurt the CDI-unit, but you never know about high Voltages above 16 Volts! And, no, I don't believe your fan(s) are causing problems with your ignition system!

The coil primary is not where the problems occur when the coils go bad. The secondary is what develops internal shorts, and would read significantly lower than the factory specified 650-790 Ohms. Or, it may go open.

Batteries boiling over are usually caused by a bad Voltage regulator and high system Voltage! Your car should have the Paris-Rhone alternator with integral (built-in) regulator, and they have been more trouble-prone than earlier alternators ... over the past few years.

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Warren Hall
1973 911S Targa

[chadwallen]

Thanks once again.
The car's current battery seems fine, even switched in my Optima from my Bronco- no differnce. I'll go with the new CDI- just hope I don't "guess" wrong again, or burn up a new one. Do you reccomend replacing w/a Bosch original or a Permatune. Will the increased spark help w/8,000 ft of altitude? We already loose 25% power just derating fuel/air mix. This brings me a little prematurely to my next question- the car is tuned at 700ft, I live at 8,000 and reguarly will drive the car over 10,000 ft.

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Chad Allen
'83 911 Cabriolet
'74 Bronco

[Early_S_Man]

Chad,

I can't tell any difference between an engine running the Bosch CDI and the Perma-Tune unit.

But, before you spring for a replacement CDI or Perma-Tune, be sure to test the output from the distributor pickup coil that triggers the CDI-unit, and BE SURE THE GREEN CABLE AND TWO-PIN CONNECTOR AREN'T BAD!!! They have been known to go out mysteriously, and Porsche sells a replacement cable and connector for around $30.

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Warren Hall
1973 911S Targa

[chadwallen]

Everything but the CD box checks out. Spun the distributer- read some ACV. Rechecked the CD box- Shows 12v at power line w/ key "on" and "start". Pin 2(tach sig) to Pin 5 (power) is open- should be 3300 ohms. Permatune tech site says that possibly a faulty tach or speed control relay damaged this part. Should I test & replace the relays? How? Pin 1 (Ground) to Pine 4 (coil hot) is open too- should be 1 ohm. Seems to indicate bad cdi. I'm leaning towards a rebuilt Bosch. I'll let you know after installing the new one.


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Chad Allen
'83 911 Cabriolet
'74 Bronco

[cwa]

She's running strong (even tuned for sea level). I had the cdi rebuilt, cheaper than a Permatune replacment. The car now starts quicker (less time w/key in 'start' position) than I can ever remember. One interesting side note- I sent the "old black" coil and the "new aluminum" coil along with the cdi for testing- both tested good. The new Brazilian made aluminum coil tested noticabley hotter. I'm running it now. I was told that alternator spikes could cause damage to the cdi. Now that the car is running I've noticed a blown hi beam on driver's side- this was replaced one week before I took the car and the radio antenna will randomly work- its currently stuck half-way up. The battery does seem to be loosing water, as all it's batteries have. I did have to top it off before leaving Ohio, I've had to add a small amount of water again to bring the levels up. Why is an 8 month old NAPA battery still "unsealed", what should I replace it with, am I risking another blown cdi? I've put two different battery chargers on the battery and neither will charge it- they indicate the battery is full & I haven't had any problems with battery power even after many failed attempts to start the car during the last month.

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[rstoll]

Better check system voltage. Make up a handy test lead from cigar lighter plug adapted to digi-voltmeter.

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Robert Stoll
83 SC
83 944

[Early_S_Man]

Chad,

More than likely ... your Voltage check will find 16++ Volts above idle, and hints of a fried regulator in your Paris-Rhone alternator.

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Warren Hall
1973 911S Targa
1992 Dodge Dakota 5.2 4X4 parts hauler

[The Edge]

Hi there!
Overseas reply.
I had kind of the same situation once ( so far). The car stop running after almost a full days driving. It turned out to be a relay in the relay box who was bad grouded or bvad connected. To choch/solve this remove the relays clean all the pins.
No oxidation allowed and of course no rust.