SteveS66

My '66 has an intermittant problem where it loses spark. I have checked things out
with a meter and have voltage up to the coil. It is an MSD Blaster II that is only about
a year old. I also checked the resistance of the wire between the coil and distributor, and
it also appears ok. So it appears the problem is either the coil or the distributor. The coil, cap,
rotor, spark plug wires, condensor and points are all about a year and 2000 miles old. How do I
check the coil to see if it is good? Anybody have any other ideas?

Thanks.

Steve

Ragin Bull

Steve,
Try calling MSD 915 855 7123. There good and patient on the phone. You can also try http://www.msdignition.com They have a "trouble shoot" section that might help you out
Good luck :cheers:

LT1driver

Check that the wire going to your points(black one)neg is not rubbing against something and grounding. i had that problem once and it drove me nuts trying to figure it out. Was off-on problem. :seeya

d1_bradley

I agree, check the wire from the points/condenser junction to the coil. Sometimes the forked terminal will short out to the breaker plate and sometimes the wire will chafe under the breaker plate and short to ground. Also be sure that the breaker plate has a good ground to the housing.

magicv8

Need more info on intermittent: :confused: Break down under hard load or high revs or when cold - plugs or wires. :crazy: Cut out when turning or over bumps - key switch, harness connection to "firewall", loose coil or distributor connection. :jester Break down only when hot - coil, points. Misfire in high humidity and when cold - wires. Etcetera. Tell us when it happens, is it a misfire or does the engine cut out...... :crazy:

SteveS66

Thanks for the ideas so far. Here is some more info. So far it has happened a couple times. In the first two, I was driving at night for about twenty minutes when the motor completely died. It took about ten minutes to restart. The same thing happened about an hour later. In both instances I had just made a right turn from a stoplight. Since then I've tried to start it in the garage a few times. Sometimes it will. The couple times it wouldn't, I connected a timing light which showed no spark. I've verified I have voltage up to the coil and I checked the resistance of the wire from the coil to the distributor, which looks ok. So I'm guessing it is either the coil or the distributor. All the electrical parts were replaced about a year ago. I think it might be a loose connection somewhere but I'm open to any other theories. I would also like to know if there is any way to test a coil to find out if it still works.

Thanks.

Steve

andy60

Steve;

Have been down that road and did not find a way to test the coil.
My problem was the coil which could only be determined by replacing it.

magicv8

When you say it sometimes doesn't start in the garage, and that it cut out taking turns - and wouldn't restart for 10 minutes - does it turn over when you twist the key, but not catch fire? If so it is ignition failure. If it doesn't turn over, it is probably an "open" electrical connection, such as a loose plug at the "firewall". All you can do to check the coil is check the primary and secondary windings for continuity. The coil may only fail when it is hot :mad . If it is leaking and (cooling) oil - replace it. Other ignition checks: (I assume you have points ignition) check the condenser, and that the ground wire to the base (at the vacuum advance) is in one piece. :crazy:

SteveS66

I did a continuity check on my coil last night and it appeared ok. I even installed an old coil and had the same results, had about the same resistance readings and still no spark. I did find a small C-clip bouncing around under my distributor cap. It turns out it was from the mechanical advance and had somehow made its way up from under the points plate. I reinstalled it but the car still won't start. Is it possible that it shorted something out while it was bouncing around? Is there any way to check if a condenser is any good? Majicmachines - the car turns over but won't light up.

Thanks again.

Steve

d1_bradley

I would look REAL close at the connection point of the condenser, points and primary coil wire on the breaker plate. Make SURE they are isolated from the plate and ground and are connected to each other. They should be attached in contact with the leaf spring that supports the moving part of the points.

magicv8

IMO it's an ignition problem. Connect a voltmeter (a digital may not display this) to the coil primary terminal leading to the distributor on a 15-20volt scale. :cool: When you crank the engine, the needle should sweep between 12.5 volts (or whatever your battery has left) and zero every time the points open and close. If there is no reading, the 12volt line from the starter solonoid to the coil is loose or fried. :mad The last 8 inches of the wire at the solonoid is a fusible link - which may be burned. To check for that (if zero volts are read at the coil) put a jumper wire in place of the other primary wire to the coil (which should be pink). When you do that, and twist the key, the engine should have all the spark it needs. :yesnod: DO NOT run the engine long like that or the point and condenser life will be shortened. :eek: The ballast resistor is the usual source of voltage to the coil, and it allows 7-10 volts. With the engine running and a jumper in place, you will see 14.5 volts instead.