Crank no start, no spark

[ike61]

Howdy. Here is what i have 68 plymouth slant 6 six with points. Car has been sitting for about ten years. It ran when parked. It cranks but wont start. I really dont know what im doing, but here is what i have:
Battery: 12.6 volts
Key on points open: -coil 11.85 volts +coil 11.83 volts
Cranking with key: 10.39-10.6volts -coil.
Cranking with key: 9.11 volts +coil
-coil, key on, wire sparks when grounded
11.7 volts key on blue ballast wire
11.6 volts key on brn/blue ballast wire
8.2 volts cranking with key blue ballast wire
9.2 volts cranking with key brn/blue ballast wire
Ran wire from battery positive to +coil no start
Check voltage when points are closed same reading as when open « most of the time ». Filed points clean. Got a lower reading a few times.

 

[67Dart273]

Sounds like the points simply are not clean enough to conduct. To tell for certain, remove cap so you can see, bump engine until points are "for sure" closed---if the are properly adjusted there will be a tiny but visible gap between the points rubbing block and the dist. cam at "maximum closed." Now measure V at coil NEG with key "in run." Voltage should be quite low perhaps less than a volt, perhaps as much as 2 v. But if much / any more the points are dirty/ worn

Also suspect a bad condenser. This has nothing to do with whether the points are conducting, but a bad or leaky cap will not "make spark."

How big is your 'town'? If there are ANY parts stores I would simply buy new points/ condenser

 

[Murray]

Coil is also suspect. Seems like there is a problem on the primary side.

 

[Dartswinger70]

Points are relatively simple. If you flied them check gap and regap. Make sure the wire to the points and the condenser connection is good. The points open and close the ground side of the coil.

 

[67Dart273]

You can check the coil. Bump the dist so points are open. Connect an alligator clip jumper to coil NEG. "Rig" a test gap to the coil tower. ALWAYS test with a solid core wire, not a radio/ resistor wire. For spark testing you don't need spark plug wire, any low voltage wire will do if you "space" it in air. Turn key to run. With test gap in place, tap your alligator clip lead to ground repeatedly. If condenser and coil are good, and coil is getting power, you should get a spark.

It is better to jump full battery to coil+ for this test. If no or poor spark, suspect condenser before the coil Do not leave key "on" and allow coil to heat up/ overheat. That can damage coils and points

To double check coil power, clip coil NEG to ground. With key "in run" coil PLUS should run anywhere from 6--10V The variation is due to type of coil, to value of ballast, and how good/ charge level of battery

If you suspect condenser and you have ANY condenser out of any battery type igntion (some magneto condernsers will work but might be wrong value (capacitance) Unhook old condenser before trying another. If the old one is "leaky" it will gum up the works, electrically speaking. The only GOOD way to check caps, most guys don't have. You need a Real By Gawd old school condenser/ capacitor tester WITH A HI VOLTAGE LEAKAGE test.

Otherwise, all you can do is buy a couple of spares and hope one of 'em is OK

"New" does not mean "working." Remember that with ANY replacement part.

 

[Bewy]

Quick test for the points.

Put a piece of thin carboard between the point contacts. Ign on, short the wire terminal on the points to ground. You should get a spark. No spark means problem is else where..or... there is more than one problem.

 

[Bewy]

Post #6 above, I should have added: you ground the terminal momentarily, then remove the ground. A spark should occur when the grd is removed.

 

[ike61]

After wasting mine and you all’s time, I've decided to install electronic ignition. I have all the parts for the swap and was going to do it next year anyways when i installed my 440 in the car. When i couldn’t get the slant started i was more curious than anything on how to fix it. So thank you all for responding!

 

[67Dart273]

You didn't wast our time. If you learned anything at all it was worth it. I used to be able to troubleshoot breaker points systems in my sleep. I once had a 340 with factory dual point, and could change points without pulling the dist although I rarely did.