The Green wire...

Brad01mc · 03-08-2007, 07:18 AM

Hi!

I finally finished installing a rear wheel bearing and took the car out for a spin. Felt great. The next morning, it wouldn't start! Later in the day, I tried again and I would start, but would just die. No sputter, just die. One odd thing I noticed is that when I cranked the starter, I noticed that the tach would jump/bounce. The last time it did this, my battery had a loose terminal (ground).

Anyway, I figured it was spark because of the sudden "death" of the engine. I read a bunch of posts regarding the CDI and decided to begin the task of trouble shooting.

I found that the infamous green wire from the dizzy had continuity across both pins, and that it was brown in areas and also cracked, with exposed wires.

The other thing I noticed, it that the green wire goes straight from the dizzy to the connection to the CDI. There is no connector anywhere along the distance.

I haven't bothered to bench check the CDI (yet) and the coil seems to have good numbers...0.8-0.9 Ohm, and 13.9 - 14.0 Ohm Primary and secondary respectively, or vise versa.

My question is...

If I get a replacement wire from our host, can I just use normal heavy gauge wire to connect it to the CDI? If not, where can I get more of this wire? and a connection that will mate with the part from Pelican?!

Also, I am thinking that I'll use this opportunity to install an MSD box (6200...I don't need the rev limiter), regardless of the condition of the CDI.

Any opinions out there??

thanks!

Brad

Mahler9th · 03-08-2007, 07:38 AM

Are you referring to about the green wire connected on one end to the distributor? If so, this is a special shielded cable... not just a plain wire. I don't think you can replace it with a simple heavy wire.

I am not sure how you can put a connector between that wire and the CDI as my set up is not stock (I have an MSD 6AL). I'd have to study the stock wiring. However, with my MSD box, I have a simple, two-conductor connector between the distributor wire and the MSD box. I have run the MSD 6A box this same way.

1982911SCTarga · 03-08-2007, 07:48 AM

There has got to be a less-expensive alternative to the "official" green shielded wire, particularly for those of us who have systems that don't have the intermediate connection (in other words, we're replacing a straight run from the dizzy to the CDI box).

Brian

Gunter · Gunter's Garage

Do a search; lots of info on "Green wire" and how people have dealt with it.
Bosch CDI is very reliable, MSD will not give you any more performance or power.
Spend the money on getting a spare CDI module.

Brad01mc · 03-08-2007, 07:54 AM

Hi!

Yes, I realize that this is a coax/special wire. I was thinking that I could connect regular wire from the connection at the end of the green wire to the CDI.

I guess my thinking is that I can probably buy a new MSD set-up for less $$ than trying to find more of the green wire. For a 6 inch tail for >$60, I'm not looking forward to buying another 2 feet!! Plus, I still need to find all the proper connectors!

My issue is with my current set-up...there is no connection/connector on my green wire...anywhere...it goes straight from the dizzy to the CDI, so I need to either replace the wire that comes from the CDI box (to where the pelican replacement wire ends) or I can just upgrade to the MSD and do what you did.

Comments?

Brad

Brad01mc · 03-08-2007, 07:59 AM

Hi!

Gunter. I did search on "green wire" and didn't find much useful info. Regardless, of the solution, I still need the fancy bosch connector that goes into the dizzy. I'm on the hook for that. Maybe this is the reason for the outrageous $$. My connector is cracked, dried out and broken. It's junk.

I'm not looking for any more power. I think it might burn a little cleaner, for smog, so my only reason to change is to avoid a breakdown in the future. It's the "while I'm in there" argument.

Thanks!

Brad

1982911SCTarga · 03-08-2007, 08:04 AM

Quote:

For a 6 inch tail for >$60, I'm not looking forward to buying another 2 feet!! Plus, I still need to find all the proper connectors!

Ditto. I made up a spare substitute green wire that I've never tested, but would attempt to use if I get a failure of my current green wire (the condition of which gets regularly monitored).

Brian

Early_S_Man · 03-08-2007, 08:18 AM

Brad,

If you can find a new connector [VW or Porsche dealer, maybe] that plugs into the pickup coil connector at the distributor, and some RG-58 or RG-174 coax at Radio Shack ... you can attempt building a replacement. Putting reliable, secure connectors onto coax is a bit of an art ... we aren't talking about an 'F' connector for a TV!

The connection at the CDI unit requires uninsulated 0.25" Fastons to replace the ones you remove from the 6-pin connector ... again, not your typical connector on coax, but it is doable. To put ends on coax reliably, you need to strip back 2" - 3" of insulation, use a pen to force a hole in the braid -- enlarge the hole without tearing the wires in the braid, pull the center wire out through the hole, then pull out the braid to one side and twist so you have two stranded wires to terminate. Both ends of the coax need to be prepped this way.

My choice would be RG-180 Teflon-insulated coax, as the PVC sheath on RG-58 & RG-174 coax really isn't up to the underhood temps of a 911!

What you want to test for at pins #7 & #31d at the CDI connector [other end of green coax] is 600 Ohms resistance +/- 10% at room temp.

Gunter · Gunter's Garage

Warren:
Do you know the actual name for these connectors with the small wire clip?

Early_S_Man · 03-08-2007, 08:39 AM

Brad,

You wouldn't happen to have a factory alarm system in your car, would you? If so, test it to make sure it still works! It may have failed and disabled your car!

You may want to read this thread:

'82 SC Won't run

Couple more ...

Ignition Troubleshooting??????

6-pin SC/Turbo CDI unit repair documentation

Early_S_Man · 03-08-2007, 08:41 AM

Gunter,

Most people just call them 2-pin Bosch fuel injection connectors ... they are used all over the CIS and Motronic systems.

1982911SCTarga · 03-08-2007, 08:49 AM

Gunter,

Eagle Day calls them two-pole female AMP Junior connectors.

Brian

Mahler9th · 03-08-2007, 09:00 AM

On my race car set up, I have one of those 2-pin Bosch fuel injection connectors between the green wire and the MSD. The wire from the MSD is just a twisted pair. So it goes: MSD to connector with a simple twisted pair, and connector to distributor with short factory green wire.

I bought a bunch of the connectors from a place called Global Metric in Belmont, CA for not much money.

Not sure whether this approach would work for a CDI, although I have a friend with a CDI-equipped race car. We re-wired it last year, but I cannot remember what we did for the distributor to CDI connection. I'll take a look.

Early_S_Man · 03-08-2007, 09:43 AM

Mike,

Would this be your source for the Amp connectors?

Global Metrics Incorporated
(650) 592-2722
519 Marine View St Ste J
Belmont CA 94002

Brad01mc · 03-08-2007, 01:54 PM

Hi!

Warren, you are awesome. I owe you a beer, some day! I'm at work and haven't had a chance to digest anything, yet. I'll respond tonight.

Mahler9th, Can't I just connect the wires from an MSD unit straight to the green wire from the dizzy?

Brad

Mahler9th · 03-08-2007, 05:18 PM

Yes, that's correct, Global Metric. They have some great metric HW, including the hard to find metric copper high-hat lock nuts, and proper metric hose clamps.

My wiring is MSD to connector using the MSD cable provided. On the other side of the connector is the green wire. MSD sell a long shielded pickup cable P/N 8862. I have one but I have not installed it yet. I plan on moving my MSD box into the cockpit.

Brad01mc · 03-08-2007, 08:28 PM

Hi!

First, thanks to all! I'm learning a lot, and these web sites are awesome! We just need to find a place that sells the Bosch dizzy connector!

Warren, When I connect up my voltmeter up to the green wire, (which I have removed from the car) I get continuity. Every combination ont the wire (for example: testing the inside wire of both ends, or put both in the same plug end), gives the same result. Continuity. Which means, what ever signal that is being sent by the dizzy to the CDI is being shorted out, right?

My new question is...

If I was not sending a signal from the dizzy to the CDI while I cranked the engine over (I cranked a fair bit, but I gave up easy) would I be damaging the CDI? What about the coil?

thanks!
Brad

Brad01mc · 03-08-2007, 08:32 PM

Mahler9th,

Can you tell me where you bought this..
"MSD sell a long shielded pickup cable P/N 8862"

I can't seem to find anything about it on google...or where to buy one!

thanks,
Brad

Mahler9th · 03-08-2007, 09:43 PM

I bought it from Summit Racing. And you can get the injector -type connector from Global Metric, listed earlier in the thread. I will take a picture of my set up tomorrow. And in a pinch I can sell one of my extra connectors. I also have an MSD 6A to sell.

Early_S_Man · 03-08-2007, 10:35 PM

Brad,

I still haven't found Amp connectors [and, I have looked for hours at the Tyco/Amp website] identical to the ones on the factory pigtail, here:

To test the magnetic pickup coil you want your multimeter sent to the 2000 Ohm scale rather than continuity. Looking at the 6-pin connector on the wiring harness with locating ribs down and beveled edge up ... the 31d and 7 terminals are on the left side.

Looking into harness 6-pin connector:

. 31d ... TD ... 31/1 ...

. 7 . . . . 15 . . . A . . . .

=================

And, no, cranking the engine with no input signal, or an intermittent one won't harm the CDI unit or coil!

At this point ... with the wiring and connectors 29+ years old, I suggest thorough cleaning of the Faston connectors with 91% isopropyl alcohol on Q-tips, rinsed with distilled water and dried, then cleaned with 9% pickling vinegar, then rinsed and air dried again as indicated in the following diagram. Same treatment for the six Faston tabs in the CDI unit connector!