Faulty Spark Plug Connectors?

[daveward]

Hi...I am reviving a beautiful 356C coupe, 1964 vintage, and I am having a starting problem. The engine/car sat unused for several years. One issue appears to be spark, or the lack of.

One thing that puzzles me is the spark plug connectors...those four plastic items that connect the spark plug wire to the plugs themselves. I have tested the wiresfrom the distributor cap to the bare end of each wire and I get connectivity. However, when I add the connector to the end of the wire I lose connectivity. I have several "old" connectors laying around and each tests for connectivity the same way...that is...if I put a test lead in one end and a test lead in the other end...no connectivity. This doesn't make much sense to me...and if there should be connectivity it would certainly explain my no spark problem. But...can every connector I own test the wrong way?

The only odd thing I can think of is some built-in resistance withing the connector...but I am no electrical wiz...so I have just reached my own tipping point when it comes to electrical matters.

Here is the simple question...when you test the connectivity of your spark plug connectors...from one end to the other...do you have connectivity or not?

Thanks!!! Dave

[craig richter]

Original Porsche spark plug connectors (with the little knob on the end to make removal easier) have a resistor inside, usually burnt out or corroded away today. Use a big screwdriver to remove the brass connector inside, and it will drop out. Replace with a section of brass tubing (I forget the dimensions offhand, but it will be obvious), reassemble, check continuity, you should be good to go.

[daveward]

Craig, thanks a million. I take it from your kind response that continuity IS a good thing. I'm not imagining the requirement afterall. Thanks so much. Dave

[daveward]

Here is a bit more discovery work. The Made in Germany 401002 connectors I have don't have the removable brass piece referred to. Further, the markings indicate 1K ohm which I tested for and got readings like .984, etc. So...while there is no through connectivity, as I expected, the tester I have will measure ohms from one end to the other.

Can there be built in resistance such that continutity is masked? Sorry for the non-technical language. Thanks.

[craig richter]

Hi Dave, I'm no electric whiz either, but I think the resistance was put in to fight radio noise from the ignition system, along with a bunch of condensers hung on the generator and voltage regulator. There have been lots of similar spark plug connectors made over the years, German and other, most not rebuildable. Yes, continuity is a good thing, even with some resistence, so you may have to source some new connectors. Real "rebuildable" 356 connectors, which I thought you had, would be like finding those proverbial "hens teeth". Best of luck.

[daveward]

I was hoping to close the loop on this and report some success...but not yet. I am still not close to solving my spark issue.
1. I found a local VW mechanic willing to talk and he confirmed our assumption that besides resistance, each plug connector should have continuity from end to end.
However...
2. He was kind enough to make me a deal on a new set of spark lug wires which included the connectors...I took them home and tested the connectors...no continuity...precise resistance...but no continuity.
3. So...now I have twelve connectors that measure the same way...and a car with no spark. Aargh.

I am treading water here at the moment looking suspiciously at my innocent looking coil... I'll update this when I get my brain around the inconsistency.

Dave

[NICE 69 S]

You can buy a set of plug wires for a VW from Rock Auto for less than $8. You will get them in a couple of days. Specify copper core if you don't want the carbon core wires that every car uses today. Put them on your motor and see what happens.
Bob B

[daveward]

Originally Posted by NICE 69 S

You can buy a set of plug wires for a VW from Rock Auto for less than $8. You will get them in a couple of days. Specify copper core if you don't want the carbon core wires that every car uses today. Put them on your motor and see what happens.
Bob B

Hi Bob, thanks for the assistance. I suppose I should have mentioned at the start that the spark plug wires I have are already new, as that seemed like a no-brainer update for a car that has gone un-started for awhile. The question wasn't about the wires, it was about the connectors. I don't mind buying more stuff if need be, but I'd like to understand that any new parts are actually different and better than the parts (some new) I already have.

I'm hoping someone might take the time to check a spare connector laying around the garage (I can't be the only one with spares) and see if the connector has continuity.

I do thank you for reading through my little story. Dave

[daveward]

I apologize if my frustration comes through here, I really am puzzled by this and I could use your assistance.

I have agreement that the connectors should conduct electricity (that's what I mean when I use the term continuity) but my tester shows that none of the older spares I have nor any of the brand new connectors just acquired have continuity from end to end. The plug wires do, the connectors do not. As mentioned before, the connectors do measure a resistance value from end to end...just less than 1,000 ohms...which means to me there should be continuity.

So...when I crank the engine checking for spark, there is none. I have an old and a new coil, I have a "spark" when the points open at a couple degrees before TDC, but the spark plugs won't react.

I am hoping someone could check a spare connector laying around for continuity or offer a suggection as to what to try next. Thanks a million. Dave

[craig richter]

do you have spark coming out of distributor cap?? Might have an open in the rotor or cap?

[daveward]

Originally Posted by craig richter

do you have spark coming out of distributor cap?? Might have an open in the rotor or cap?

Thanks for asking Craig. I'm not sure how to test for that other than to do what I've done...to remove the spark plug and reconnect it to the spark plug wire leading back to the distributor. With the plug grounded I turn over the engine which spins the distributor which should create spark at the visible end of the plug.

It seems to me that this is the test you are speaking of...meaning spark coming from the distributor. If you mean something else, please let me know. Thanks.