Part 2 - '90 80q randomly stumbles and dies: bad ignition coil?

[Darringer, Chris]

At the recommendation of a lister, I took a close look at the engine running
in the dark.  Once your eyes adjust to the darkness, I was actually
surprised to see small blue "sparkles" in a half dozen places on the engine!
I would not characterize this sparkling as high-voltage arcing, but some
kind of small electrical "leaking".  The only time I have seen this before
was on an old Tesla coil I had:  250,000 volts would jump between two
points, but if you separated them with enough distance, the arcing would
stop, but the two points would continue to "sparkle".  Anyway, I am not too
concerned about this (at this point the engine was still running smoothly).
I would recommend looking at your engine in the dark to anyone with too much
spare time on their hands, though.

Continuing my research, I pulled the ignition coil wire out of the ignition
coil, and was surprised to see considerable corrosion all over the contact.
I also found that my 1 year old Beru ignition wire had a crack in it near
the contact.  My assumption at this time is that the contact with the
ignition coil was bad, and this lead to a short between a coil terminal and
the crack in the ignition wire.  I cleaned the terminals and contacts,
wrapped the wire with electrical tape for now, and so far the problem has
not returned.

My impression at this time is that ignition coils typically don't fail.
Ignition wires and their contacts, even new ones, are the most likely
culprits for these kinds of problems.  Watching in the dark is very
revealing, although spraying water from a Windex bottle at the same time did
not induce arcing in this case.  Finally, after watching blue sparkles for
15 minutes, I now have more respect for people who buy those expensive
ignition wires with industrial insulation.

Thanks,
Chris
'90 80q

>>I have a pretty annoying problem right now that has left me stranded three
>>times.  Here is what I know:
>>
>>(1) Car will run fine most of the time.  Every once in a while, a few
>>minutes after driving, usually during acceleration, the engine stumbles
and
>>dies.  Restarting the car is hard, but after a dozen or so tries, the car
>>stumbles back to life, and is eventually fine for the rest of the day.
>>
>>(2) When the car was stumbling the last time, I heard a "clicking" sound
>>near the ignition coil.  The clicking sound was the same frequency as the
>>car's ignition timing.  When the clicking disappeared, the car was fine.
>>Sounded like high voltage shorting to me.  I twisted the ignition wire,
but
>>that did not have a significant impact on the clicking.  I also moved a
few
>>nearby wires away from the ignition coil - this also did not change the
>>stumbling significantly.
>>
>>(3) On occasions where the car died, it was either raining or there was
>>significant humidity in the air (maybe a coincidence).
>
>Probably not. Try misting the coil with water from a windex sprayer
>and see if it dies. Try at night and you'll see the sparks quite
>clearly.
>
>>(4) Before car died, it took an extra second or two to get the car
initially
>>started.
>>
>>(4) Ignition wires are about 1 year old.
>>
>>(5) Distributor cap and rotor are new.
>>
>>(6) Fuel pressure and timing have been measured when car is running
>>correctly, and are within spec, although fuel pump is on its last legs.
>>
>>So, are these symptoms of a bad ignition coil?