[FC] Intermittent engine turning itself off

[Larry Forman]

Hi Steve,
Since it is a repeating intermittent occurrence, then this is a perfect 
application for instrumentation.   What might help is to take a 
multimeter and connect it to one of the suspected connections.  However, 
before we go there, I would highly recommend swapping the coil for a 
known good one.   Regarding coils that might even be a little suspect, 
my motto is:  if in doubt, swap it out.    Since these can be swapped 
out in a matter of minutes, and since they are one of a few things that 
can stop you immediately, then carrying a spare makes sense.    These 
can be easily swapped on the side of the road quickly.

Back to instrumentation.   If you take a multimeter and a long wire, you 
can keep an eye on that coil voltage when running.   Just make sure the 
connections are well connected and will not give you a false indication 
of a problem.   When the car stops, you can see if the voltage at the 
coil has gone away or something else.   Keep in mind that once the 
engine totally stops, the points could be either open or closed.  If the 
voltage source has an open, then the voltage at the hot end of the coil 
will become zero volts.

Being able to monitor the voltage and seeing what happens right as the 
problem starts, can help identify what is happening.

Coils can certainly have intermittent connections inside them, which can 
cause these symptoms.   I would swap the coil as a first thing.    
Another thing I might do is to look in the engine compartment and see if 
you can move some of the wires associated with the engine electrical 
connections.   I help solve this type of problem in a Late model and I 
could see arcing in the electrical wiring by the battery side when the 
engine ran rough.   There was something shorting the wiring and finding 
that arcing made for a simple taping solution to the problem.

Good luck and let us know what you find.

Larry Forman

On 11/25/2011 8:08 PM, J R Read wrote:
> Steve,
>
> I suspect a wire that either shorts (probably) or completely looses contact
> (possibly) somewhere as the engine warms up.  Could be a bad coil, but I
> don't think so because 4 instances in 3 miles just does not sound like the
> typical weak coil symptom.
>
> Look at the wire going to the coil as it passes through the distributor.
> Also look at the connections (and strands of wires) at the coil connections.
> There might only be a couple of strands making contact just before the spade
> connector.
>
> Later, JR
>
>
> ----- Original Message -----
> From: "Steve Turner"<imakarknut at yahoo.com>
> To: "Corvanatics"<corvanatics at corvair.org>
> Sent: Wednesday, November 23, 2011 7:27 PM
> Subject: [FC] Intermittent engine turning itself off
>
>
> Hello gang; I took the '61 Rampside out for a ride today since it was sunny
> and only a bit chilly here in southwest Michigan. I drove the Rampside about
> 6 miles before a symptom that I had experienced this summer reoccurred. The
> engine stumbles, the gen light comes on causing the truck to slow, then the
> engine kicks in, the gen light goes off and things are okay. After 6 miles
> the problem reoccurred at irregular times, but in the last 3 miles home it
> must have occurred at least 4 more times. Last summer I had thought that the
> weight of the key fob I had attached to the ignition key might be the cause
> of the problem, causing the ignition key to be pulled a bit away from run
> position. I checked this out on the way home today and found that it did not
> seem to be related at all. I have not done anything else to check for the
> cause. Any leads as to probable causes? Since it seems to happen once the
> engine is fully warmed up could it be
>   coil?, fuel pump? what else?
> Many thanks in advance. Steve '61 Rampside(with car engine), '61 Lakewood
>