1930 coupe - no spark at points

C

coyledad46

Member
I installed a newly rebuilt engine in my coupe over 20 years ago, but never fired it up. After retiring, I wanted to get it going. I added a fuse block, new coil, points, point block,condenser, plugs, lower distributor plate, pigtail, distributor cap, etc. I also replaced the carburetor with a rebuilt one, fixed some leaks and so on. I started the car several times. I wanted to test out the brakes and clutch, so I drove it down the street a couple of blocks and went back to the house. It stopped running and I haven't been able to start it since.
Voltmeter checks OK in all places, except that I get no (actually extremely little) voltage on the point arm, the points won't spark, and there is no spark when the high tension lead from the coil is grounded on a head bolt while turning the engine over. Any help would be appreciated.
Thanks
 
Check the little wire under the distributor plate first. Notorious for shorting out under there.

Steve
 
Steve--
Thanks for the quick reply. Here are some photos. If anyone sees anything that seems like it could be a problem, please let me know. I replaced the lower plate with a new one. The new upper plate was too thick to fit in the groove, so I re-used the old one with new components mounted on it. The old wire was patched with tape, so it was replaced with a new one. Thanks for your help.
 

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you say that voltage is good at all places? but no spark...

not sure what you mean by all places, but one should be able to diagnose a no spark condition with a meter or even testlight.. certain things happen differently depending on wether the points are open or closed...
 
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Looking at the photos it appears that where the wire attaches to the upper plate might be positioned where it will short out to the casting. Loosen the nut and rotate the wire so the lug is facing inboard. Tighten it, then bend the lug up so it is vertical. This way it will be in a position to not short when you move the spark advance handle. It will also lock the nut into place.

When you have the distributor back together. Place a piece of paper between the points and clip an ohm meter lead to the arm of the points, with the other lead to the casting ground. Move the spark advance arm through its travel to see if it shorts out. If it is good to go remove the paper and with the points open there is still no short, and with them closed it should show continuity.

Tom Endy
 
It's probably not causing your problem but I think you have the flag terminal
on the lower plate wire about 90 degrees off. See the picture of Marco's distributor.

Bob
 

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Hi--
Thanks for all the responses. Where the wire attaches to the upper plate, I tried turning the lug and bending it up, but it didn't change anything. Still no spark at points. Here's what I meant by voltage being good at all places: 6v at pass side terminal box nut, 6v at driver side terminal box nut, 6v at pass side of coil, 6v at driver side of coil. But -- with key on and paper between points, no voltage on points arm and no spark when I open points with the paper removed. I had put in a new condenser and replaced it with another new one, but that didn't change anything.
 
coyledad46 said:
Hi--
Thanks for all the responses. Where the wire attaches to the upper plate, I tried turning the lug and bending it up, but it didn't change anything. Still no spark at points. Here's what I meant by voltage being good at all places: 6v at pass side terminal box nut, 6v at driver side terminal box nut, 6v at pass side of coil, 6v at driver side of coil. But -- with key on and paper between points, no voltage on points arm and no spark when I open points with the paper removed. I had put in a new condenser and replaced it with another new one, but that didn't change anything.
Click to expand...

ok better information.... are you running an original style pop out ignition switch or a 2 prong after market?
 
with the points open key on the power has to travel through the ignition switch to the dist..
common issues are bad switch
switch terminals touching the fuel tank grounding out
cable screwed to far in the distributor ...
the power then travels thru the lower plate wire to the points arm....

again the points need to be open key on....
 
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Hi --
It's not a pop out. It has a plug (almost looks like a piece of pipe with one end threaded) that screws into the distributor base with a plunger and spring on the end. A single wire goes from there to the dash. This is the set-up I've always had on the car.
 
coyledad46 said:
Hi --
It's not a pop out. It has a plug (almost looks like a piece of pipe with one end threaded) that screws into the distributor base with a plunger and spring on the end. A single wire goes from there to the dash. This is the set-up I've always had on the car.
Click to expand...

With the key switched on you should have 6-volts at the tip of the plunger. If you do, then the problem is inside the distributor. Somewhere the voltage is shorting, or something is open.

If you do not have 6-volts at the plunger, you are more than likely losing it at the key switch.

Tom Endy
 
The wire that connects the 2 dist plates doesn't look "kosher" to me. Check for continuity from one end to the other. Then bend the wire and ck continuity again. FWIW

Paul in CT
 
Again, thanks for the help--
I do have six volts at the plunger. So I guess the problem is inside the distributor. I'll take it apart again and see if I can discover anything more.
Will let you know.
 
Will someone please tell him to screw the wire with the plunger on it to only screw it in about three turns and no more than that!!
 
The ignition wire with the spring plunger can push the lower plate tab in against the housing and short out as was mentioned above. Remove the lower plate, and glue a piece of tape on the back side to prevent this form happening, and as said earlier this ignition wire only has to go in a few turns to make contact with the tab. This is very common on the modern style points because there is no condenser on the end of the tab to stop it from moving against the housing inside.

Here is a picture of the under side of the lower plate, the dark area you see on the back of the tab is friction tape glued on for an insulator.
 

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The reproduction lower plates I've seen are much thinner than an original. I always use an original plate and fasten a new wire to it.
As mentioned, I also think the problem may be the ignition cable was screwed in too far.
 
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