Technical Model A has no spark. Any suggestions gratefully received.

My Banger-engined 1930 Model A Pickup has no spark. It is a stock engine, have replaced the points plate, new points, resoldered the pig-tail wire, new condenser, good sparkplugs, distributor body checks out, timing is right, good snap from the high tension lead when earthing the points. Tried everything, including sheathing the pig-tail wire to ensure no accidental grounding. Someone said to eliminate the rubber washer at the end of the condenser, but not sure about this. I am in New Zealand. Thanks in anticipation.

 

Do you have power at the coil?

 

Sounds like there are two more things that could be checked...since you say that you have a good snap from the high tension lead when you short the points.
Is the distributor shaft turning? and if it is...
Are the points really closing as distributor rotates?

 

Thanks for the replies, yes, power at both sides of the coil, and points are opening and closing, the new aftermarket points plate has a bit more movement in it, is in when the advance /retard lever is used it may be changing the points gap, but that is all I can think of.

 

Make sure the points are clean and grounding when they close, since they fire when you short them it looks like they either aren't closing or are contaminated and not grounding the coil.

 

Okay, with the points open you should have power at both terminals on the coil. Now crank the engine over to close the points, you should have battery power on one side of the coil and none, 0 volts, on the side going to the points. If you don't have 0 volts on the point side of the coil, there is no connection between the wire going to the points and ground. Try running a jumper wire from the point connection to ground. If the coil terminal now goes to 0 volts you have no ground for the points. If it stays at battery voltage, your wire to the points is open.

 

Thanks, Americans!!!! Yes, power to both sides of the coil, with zero voltage with the points closed. The points are new, but I cleaned them up anyway, just in case. Will perhaps try the old points to see if any change. . Many thanks.

 

Put the rotor back in...
You need to verify static timing with the lever retarded, and if the rotor is just before #1 as the timing pin drops into the dimple on the timing gear, you are good.
1, 2, 4, 3
Pull a plug and verify a spark
Then it has to be fuel or compression

 

Thanks for that, will check again, I am wondering if there might be corrosion on the spark plug tops where the brass strip goes on. I just pulled one off, cleaned it, broke the retainer, tried another plug and the thread broke off inside the retainer!! The joys of Vintage Motoring I think they call it........

 

my 2 cents: check the amp meter and is the pop out switch grounding?

Mike

 

If your getting spark with the cap off at your points when you open it up with a screw driver from close - then I would look at the cap. And if it was running before the new parts - maybe go back to find what was replaced that is bad.

 

Get a test lite and ground to the block and move dist so points open lite should activate . Then ground to the dist housing . Ma be dist housing isn't ground

 

Thanks Mike, The amp meter should move when the engine is turning over, mine is not. I have a non-pop out switch, but it checks out OK.

 

Thanks for that, I just remembered it was running with the new points, etc, in it when it cut out and coasted to a stop. That makes it even more perplexing.

 

Many thanks, will try that.

 

Some of the aftermarket rotors need tweeking to get the alignment and gap set correctly. Easy to check on an A distributor cap

 

Make sure it's wired like in this schematic. It works for everything!

 

Thanks, I am trying to use as much of the original parts as possible, such as rotor, cap, etc, so hopefully it should be OK.