A few weeks ago I queried this list when my Healey stopped abruptly in the
last few blocks from home after completing several hundred miles of weekend
outing. Today I finally had time, with help of a friend, to run some
diagnostics
and locate the problem.
Immediate symptom: No spark produced, using screwdriver in spark plug wire
test.
12 volts at coil input, check.
Substituting a known working coil didn't solve problem, so probably not coil.
Dwell meter on coil wire yielded 40 degrees steady dwell, so points working
all right.
Removed distributor cap and checked inside: Gee, center part that secures the
graphite brush from the coil wire neatly broken off 1/8" from top, with
graphite brush long gone.
Replaced distrib cap with known working cap and wires. Still no spark.
Looked at rotor again. The center of the brass portion, just where it would
normally touch the graphite brush, was totally worn away, with a neat circle of
plastic showing through.
Replaced rotor.
With new rotor and distrib cap, car started right up.
Now searching for theory as to why a rotor and distrib contact to the rotor
would fail simultaneously. Did the rotor wear through, breaking the distrib
cap, or did the distrib cap break, wearing the brass off the center of the
rotor?
Once again, proves the old truism: "Just because you've found and solved a
problem, doesn't mean you've solved the problem you set out to solve."
Cheers
Gary
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