Re: points and condensers

[Scott Fisher <sfisher71@domain.elided>]

--- James Montebello <jamesm@domain.elided> wrote:
> Anyone have any ideas on where to proceed from here
> (besides just buying all the parts and swapping, 
> this is partly an educational exercise)?

...Alfa-specific question: how new are the plugs?  A
standard problem on older Spica-equipped Alfas is for
the plugs to foul, particularly if the car sees a lot
of short trip use.  We've seen it get so bad that the
plugs would not fire, even when held out of the car on
the plug-testing fixture.  Jeff and I have each been
bitten by this a couple times in the past months.  Put
in four new, properly gapped plugs and see if the car
starts.  If it does, schedule some time with a Spica
guru to have your mixture adjusted -- it's probably
too rich, and your plugs are fouling.

If that doesn't solve the problem, it's time for the
Maestro's binary search (named after Harry Pellow, aka
"The Maestro," a 356 engine builder in Santa Clara,
CA).  This splits the diagnostic work in half, so that
you immediately eliminate half of the possible causes.

First, determine whether the coil is firing or not. 
You can do this with a timing light: put it on the
coil HT wire (the big wire going from coil to the
middle of the distributor) and have someone crank the
engine.  If the coil is firing, the timing light will
flash.  If the timing light stays dark, it means your
coil is not firing.  Either way, you now know where to
look.

If the coil is firing but the plugs are not, your
problem is either in the cap, the rotor, the plug
wires, or the plugs.  If the coil is not firing, your
problem is in the points, condensor, distributor, or
coil.  Either way, the timing light will eliminate
half your potential problems.

If the coil is firing... you can get some relief by
simply cleaning all the connectors from the coil wire
into the cap, both "ends" of the rotor, the spark-plug
terminals, plugs, etc. etc. etc.  I used to have a
sort of abrasive rubber eraser that was designed for
cleaning brass connectors such as the end of the
distributor rotor.  If you can't find one of these
rubber thingies, 600-grit emery paper works quite
well, but my recommendation is that if you determine
that the coil is firing but the plugs are not, just
buy the damn tuneup parts. :-)

If the coil is not firing... first, make sure the
rotor is actually turning in the distributor (I *have*
had distributors jump out of the block on me, though
not on Alfas.)  If so, there are tests you can run
with a test lamp or volt-ohmmeter that can help make
sure your points are opening, closing and transmitting
current at the right time.  Step 14 on the AROO tuneup
page has some info about this:

http://www.alfaclub.org/techstff/tuneign.htm

This will help you make sure the points are opening
and closing, and also gives indications for how to
determine the right timing in case that has slipped.

Note that sometimes, buildup on the points surfaces
(or erosion of the contacts) can interfere with proper
operation, even when the points look like they're all
right.  If you aren't going to replace them
immediately (and if you're not, you should simply give
the Berlina to somebody who will take care of it),
grind them flat with a points file (or any
fine-grained needle file) and re-gap with a good
feeler gauge once you know the surface is clean and
conductive.  

...But.  While it's commendable to track the problem
down to see exactly what component is not working so
that you learn valuable diagnostic skills, all the
tuneup parts -- points, rotor, cap, condensor, plugs,
and to a lesser extent wires and coil as well -- are
meant to be changed out on these cars to keep them
running their best.  Ignition components are like oil
filters: designed to be used up, then replaced. 
Moreover, they're designed to be replaced at about the
same time because they wear out at about the same rate
-- so if it's the condensor that's gone out now,
replace it and you only delay having the car quit when
the points wear out, or the rotor, or the cap, or...
you get it, I'm sure.

So once you really understand what's going on and have
identified the culprit, drive down to Jon Norman's and
pick up a full tune-up kit -- points, condensor,
rotor, cap, new plugs, wires, and if you're feeling up
to it, a new coil too.  (Don't forget the air filters,
either.)  With your newfound familiarity with the
system, it should be a piece of cake to install
everything.

Best,

--Scott Fisher
  Tualatin, Oregon
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