I just had an odd thing happen. I just set timing and plugs to specs and
took out for a run. The engine was running noticeably better and I ran it up
to about 95 mph (I know. I have heard that the police take a dim view of
such activities). I started slowing down and suddenly lost all power. I
drifted off the side of the road and stopped and at that time received the
final engine protest, a tremendous backfire through the exhaust. I waited
a bit, started it and ran it home with plenty of power and no further
problem. I have a 65 SC with a 63 super engine, IDF 40 Webers and a
Cranecam electronic ignition. I have had no such problems before. Does
anyone have any ideas as to what might have happened? This has never
happened before but I have never pushed the engine that hard either.
Sometimes when you replace the points especially Bosch and especially an
electronic ignition the oxide coating that develops on the contacts while
sitting on the store shelf can interfere with the connection. Clean the
points with a point file or some very fine sandpaper. The large amount of
current passing through a congenital system will have a cleansing effect.
The Stable, San Francisco
I would like to make an alternate suggestion, based on a career in
Points should not be cleaned with something like sandpaper which removes
metal. True "point files" are burnishing tools. A burnishing tool is
NOT a file - the "teeth" not not have sharp edges and the effect is to
sort of "roll" displaced metal back down into a smooth surface. But
even that should not be used to clean points which have only surface
Points which are not in use, as Alan says, are subject to contamination
from atmospheric exposure. In addition to the possibility of corrosion,
a minute coating of something oily will form on points which are stored
and do not have the advantage of being cleaned by the heat and minute
arcing caused by breaking the flow of current.
One good technique is just to pass a strip of heavy paper between the
points. That will usually do it. Of course, this would only apply to
two-piece points if they are installed and under spring force as
"one-piece" points are whether or not they are installed.
My favorite chemical point cleaner is called "Cramolin." It is not just
a de-greaser, as so many point sprays are. This is a sophisticated,
aero-space derived formulation which actually dissolved oxides. I have
never seen it available through automotive supply sources; I buy it
through electronics supply places.
The Stable wrote:
>I just had an odd thing happen. I just set timing and plugs to specs and
THEN the MAESTRO wrote:
[ From your description of the Problem- especially that part about the
Tremendous Backfire, the cause is clearly Electrical. Likewise the sudden
cut-off of all Power.
Since you just did a tune-up, Chances are high someting you did during
the tune up caused this. I'd re-check everything you touched. It could be
something as simple as a loose connection at the Coil or in the Distributor-
especially if you have a "stock" distributor with the insulated through bolt
(and insulation on the side of body where the point spring goes, or the
little "gripper" that grips the points that can twist and ground out. The
Backfire might have jolted it.
Secondly, when debugging engines with an electronic ignition, I
disconnect the electronic ignition. It's sadly surprising how often the
Problem IS the eletronic ignition itself!]
Be sure to check the back of your ignition switch for a loose terminal 15 wire
(output to the left side of the ignition coil). If the wire is loose in the
bullet connector or there is no bullet connector (as was the case with my 1964 C
coupe), any bump you hit can cause momentary loss of ignition to the engine.
This also produces the symptoms you describe.
64 C coupe
65 C coupe