Date: Sun, 12 Aug 2012 16:16:13 -0400
Reply-To: David Beierl <dbeierl@ATTGLOBAL.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@ATTGLOBAL.NET>
Subject: Re: Burnt Ignition cable end stuck in dist. Cap
In-Reply-To: <5027fa1f.0253650a.63b9.fffff850@mx.google.com>
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At 02:46 PM 8/12/2012, Edward Maglott wrote:
>12,000 miles old. I got the end piece out, cleaned up the cap and
>put my old coil wire back on and now it's back to running fine. I'll
In a sense the mileage is irrelevant. Once you get an arc that
starts burning the plastic of the cap it can only go downhill from
there. In practice it may be fine forever or you may have the
beginnings of an electrical puncture that will reach the outside at
some inconvenient time. Once the insulation is breached by the
electrical pressure, it remains permanently damaged - your finger
will find it even though it may be invisible or nearly so, and it
will leak if given a chance.
Other than a defective terminal like yours, a wire that's partially
plugged in is the easiest way for this to happen, and the coil tower
is probably the most susceptible, because it's out of the way and
with no visual comparison with other wires, it has a short path
through the side to the grounded case, and it gets all the sparks
instead of getting to rest for three out of four.
A good general check on your ignition wiring is to wait for a damp
foggy cool night and then watch the engine in the dark right after
you start it from cold. Anything that lights up, shouldn't. A dry
night may provide additional information, I'm not sure. Certainly
anything that lights up in the dry *definitely* shouldn't. A reverse
check is spraying WD40 on cap and wires to see if behavior improves.
You can no doubt save the wire if it's otherwise in good shape by
putting a new end on it if it's otherwise in good shape. The
old-style terminals are easy to come by and FLAPS-type wire crimpers
can crimp them. Modern silicone-covered ignition wires are
electrically wonderful, but the internal conductor is basically a
carbon-coated string with little mechanical strength. You have to
strip it back and fold it over the side of the insulation as you slip
the terminal on. The newer spring-type terminals are much superior
and not so inclined to tear off when you remove the wire from the
cap, but I don't know whether they're available locally or only from
the Bosch Fairy; and I haven't examined how they connect to the wire.
In all these high-voltage connections, dielectric grease is your
friend. It seals out moisture and also keeps moisture from wetting
insulating surfaces to provide an easy conducting path. Bosch says
to put a thin layer on the ceramic spark plug insulator when
installing, as well as on connecting towers.
It has been argued here in years past that only Bosch wires were good
enough for our beloved beasts, none other need apply. I think that's
based in emotion rather than fact; all modern ignition systems
require extremely high quality high-voltage wires and such wires are
available from many sources. Nippon-Denso and NGK are OEM suppliers
for Japanese automakers just as Bosch are for German ones, and it
could be argued that they set the standard for Bosch to look up to
and not the other way around. When I had my '84, before I switched
to the later-style coil and cap with male terminals, I was
particularly disimpressed with the $$$ Bosch "single-use" wires that
would rip off the terminals when unplugged from a Bosch distributor
cap. First time I'd ever had that problem, and those terminals have
been around since the '30s, I think. Clearly they didn't think hard
enough when shifting to their particular soft silicone insulation
compound (but the newer terminal design is excellent).
Yours,
David
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