1983 ignition cable questions

[SCWDP911]

I have an 83 with basically stock 3.0L. Original type ignition cables still on it. I have a miss while accelerating that lead me to watching my cables at night and I found the first one on the left side (Looking at engine) is arcing against a hard line stainless tube (oil line?). I am also seeing a "travelling" blue arc appearing on the cables coming right out of the dist. cap. I say travelling, because it seems to be moving around a bit. I have decided that I probably need a new set of cables. But, I also wanted to see about testing just to make sure. What resisitance should I see on a typical set of 911SC wires? Also, is there any way to insulate that first cable with a rubber splicing tape, to get by until I have time to change these out? And finally, those with experience on the SC motors, it looks a though I will have to remove the hoses that run over the top of the left side of the motor in order to get to the left side plugs. Realistically, how long should this job take?

Thanks

[Jay Laifman]

I know there are three options out there. There are the stock metal braided covered wires. There are the Magnecor wires. And, there are Nology Firewires. People seem to uniformly trash the Nology wires. So, they are a no go. There are those who say that Magnecor are great and that the braided wires turned out to do nothing. Then there are those that take the factory's position that the braided wires actually do something for CIS cars to avoid airbox damage.

My factory wire ends kept going bad. I had replaced 3 and had another go bad. For a little more than the cost of the 3 left, I got Magnecors. They worked fine. In trying to track down a problem I was having, someone who I completely trust insisted on factory wires. He said get the newer type of connectors because they always had problems with the older style. The older ones screw onto the spark plug wire, the newer ones are clamped on.

I had easy access to three new ends of the older version. So, I got those to get my original wires going. Sure enough, on testing the ohms, one was bad! So, I decided to pay up for a complete new set with the new type of ends. It is beautiful workmanship and looks so good in the engine compartment. Of course, it made no noticable performance difference over the Magnecors. I will say though that the ends of the Magnecors are much bigger and make it easier to get them to find the spark plug down in the hole because they can't go as much side to side as the smaller stock ones do.


The resistance for factory stock wires is 4k ohms per wire. For wires like Magnecor where there are resistors built into the wires, it changes by length, usually like 3k ohm per foot.

[Jay Laifman]

Oh another way to tell the difference between the new and old connectors is that the old ones that screw on have the wire going straight into the plastic connector. On the newer style, there is a small rubber boot that the wire goes into and it covers the top of the plastic part.

[Superman]

It won't take long to remove those hoses. If you have A/C, you may also need to remove or move the compressor.

The distributor ends are 100 ohms. The spark plug connectors are, I believe, 3000 ohms. Total of 4000 ohms. I'm guessing a little, but if you test all six, you'll see what the number should be. It is not unusual to have a failed connector (infinite resitance).

I am still using the stock system. I have removed the stainless steel webbing. It is really not necessary. When a connector fails, I replace that connector. I have spare connectors, and I travel with them. I also replace the cable periodically. You will need a couple dozen feet of bulk 7mm cable. Motorcycle shops almost always have this. The screw ends that screw into the spark plug connector are special parts, but they can be found. Either Porsche or Mercedes Benz. They will sometimes crimp them on for you as a courtesy. The special tool for this is necessary. It is far better to have them do this with the special tool than to try it yourself with pliers or something. Only six are needed. Buy two more and have them crimped onto the ends of a six-foot section. That way, you have basically two spares.

And replace your cap and rotor regularly.

[SCWDP911]

Thanks guys... this was the type of info I was looking for. As a side note, should the boot on the plug end be that wobbly. I mean, if I pull on it, it feels like it is seated on the plug, but I have never had a plug cable be so wobbly like this (specifically I am doing this to the first plug wire on the left side). I looked at another guys same wire on his carrera the other day and it was not quite as wobbly, but again, not all that stiff either.

Also, how much "umph" factor is there involved in removing the boots?

Thanks again...