Ignition Problem?

Robert/Texas

Robert/Texas

Well-known member
When I tried to start my engine, the ammeter showed a slight discharge as it always does but when I cranked it with the starter and with the spark retarded it started to crank normally but suddenly felt like the spark was at full advance. I noticed that the ammeter was no longer showing any discharge, so I checked the voltage at the point arm. It showed 6.2 volts, but the ammeter still did not register so I replaced the 6-month-old condenser with new one.

Now the ammeter registered but the engine still wouldn’t fire. I removed the timing pin, and I could feel the dimple as I hand cranked it. I saw that the distributor rotor was turning.

Before I start tearing into this, I would like some help/suggestions.
This is a stock ’28 roadster with the original style points.

Thanks in advance for your assistance, Robert.
 
Do you show 0 volts with key on and points closed ?

Remove secondary coil wire and place it 1/4" from a good ground.
Turn so the points are closed and put a piece of paper between points.
Turn key on
Open and close points and see if the coil wire sparks. It should.
 
Thanks Patrick, I tried what you suggested and couldn’t get it to work. Then I checked the voltage again at the point arm and it fluctuated between zero and 0.2 volts. The next try it measured zero volts. Later I checked point arm again and got 6.2 volts. Then I tried what you suggested, and again it didn’t work, and it had lost the 6.2 volts at the point arm. My 86-year-old brain is having trouble figuring this out, but I think that I might have another bad condenser.

Does it seem probable that when a condenser goes bad while cranking it would suddenly act like the spark was fully advanced?

Robert
 
Well, I recently went thru 5 new condensers until I got a good one. These were the 'good' condensers, they must have had a bad run.

But, it seems like your problem is in the ignition primary before the condenser. I'd recommend checking everything from the coil thru the switch and the primary lead to and into the distributor. The switches can 'crud up' [ technical term] and usually a good cleaning fixes them. The insulation in the primary lead/cable can go bad and ground/short. The primary lead/cable can even be screwed into the distributor too far causing a ground/short.
With the points open there should be battery voltage at all times. With the points closed there should be 0 volts at all times. [ key on]
 
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Thanks again Patrick. I just put in the third new condenser and the car fired right up with a cloud of smoke from all of my previous tries.

Robert
 
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