Update on the intermittent distributor short - now it's disappearing spark (help!)

[SDJason]

Well, it's the weekend again, so I had time to take yet another look at my mysterious electrical problem.

I seemed to have solved the intermittent short (how - I'm not really sure; it just disappeared at some point and I didn't do much other than take apart & put back together the distributor innards 4 or 5 times while trying to find the short). I was hoping that would be the end of it, but nope.

Now it appears that I can only get good spark for a few revolutions of the engine - not enough to start, and then spark disappears. I've tried just manually opening & closing the points and can get good spark consistently, but when I use the starter, spark disappears within a second or two (discovered by manually pushing in the starter button while leaving the coil wire close to a head nut).

Going back to manually opening & closing the points, though, generates spark! I'm really perplexed by this - in my mind, if there's spark there, it should stay there!

So - I once again am throwing this out to the forum - any ideas?

Thanks again (and may you never experience this yourself)…

[msmaron]

start with a logical trouble shooting sequence and start at the battery and work forward, check every single thing, the battery ground, cables, starter, ground nuts and bolt and keep working forward, get les andrews book and follow the primary circuit, when you know that is GOOD and working go to the secondary circuit.....you WILL find the problem and good luck..just DON'T DIVE BOMB and go here and there and everywhere...you wont find it like that...

[Tom Wesenberg]

What you have is exactly what I had two years ago when my Model A was parked for about 6 weeks during very wet weather. After sanding the points it still wouldn't fire with the starter, even thought it cranked real strong. So finally I just turned the key on and gave the hand crank one pull up and the car was running. After it ran for a couple minutes I shut it off and tried the starter, and it fired right up. Sometimes those points just want to make you have to use the hand crank.

We still have snow, but it's finally melting, so maybe I'll get it out in a few more weeks.

[P.S.]

First guess is a bad connection in the DC system or ignition switch. It could also be a condenser that has a carbon trace inside.

[Mitch//pa]

without dive bombing try this quick diagnostic step. run a jumper wire from the negative of the battery to the black wire on the coil and see if it still does it. (that is how we hot-wired cars back in the day and then only had to jump the starter solenoid)

assuming you have a stock pos ground system

[walt jones]

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Good sugestions above. Mark's method of logical trouble shooting is essential. If electrical checks are good, then look at the mechanical. Check for warn distributer bushings. Warn busings can allow the distributer shaft and therefore the distributer cam to move away from the center to one side, this can cause problems with the points opening and closing properly. Part of the time every thing is fine, then as engine cranks over the distributer shaft moves in its loose bushing and the point gap is changed or eliminated alltogether. Then distributer ceases proper function.

[Mike V. Florida]

Originally Posted by 1930 coupe

A WEAK BATTERY will do that.
Just enough power to crank slow but voltage is too low for spark while cranking.
The voltage goes down while cranking.
Try using the hand crank or push start to test.

This is also the first thing I thought of when I read your post.