No ignition spark on 1940

[Garyr1016]

I would normally start at the coil and work forward to the spark plugs to chase the problem. But my question is, What typically goes out on these cars? I could just start replacing stuff, but would like to isolate the problem first.

Here's the situation,

I'm working at getting a 1940 model 50 running. The car has set for a long time, I've replaced all of the fluids and cleaned and overhauled the fuel system from gas tank to and including the carburetor. Now to check the ignition system. While cranking the engine (ignition switch "on" and remote starter switch bridging the carburetor vacuum switch) there is no spark at the spark plug. Also no spark at the contact points, as I recall there should be some arcing at the contact points if the engine is cranking and the distributor cap is removed

Any easy place to look?? Is it possible to test the coil, should I just replace all of the plug wires?? Will a faulty condenser kill the spark??

Comments and/or advise on how to proceed.

Thanks

[groselle]

I had a very similar problem recently. Trying to start my 1936 Special that hadn't run in 40 years. I had no spark as well. There was voltage coming to the coil but no spark from the coil. I replaced the coil and bang she started right up. I would remove the wire from the coil to the center of the distributor and see if it sparks against the valve cover. If not, I bet its the coil. You can get a new one from Bob's Automobilia or I think even Checker Auto can order one for you (that is if you can find a clerk that is willling to forgo the computer and look in the books under the counter). You can see my progress at the link below.

[Matt Harwood]

Also make sure your distributor isn't grounding out and that the cable from the ignition switch to the coil is intact. I had a nightmare of a time trying to get my father's Model A Ford to run, and it turns out that something in the distributor was grounding where it shouldn't. I replaced coils, points, rewired the ignition system, new plugs, new cap & rotor, new plug "wires" (they're copper strips, but I replaced them anyway), new ignition switch, everything new. Still nothing. Then I just took the distributor apart and put it back together. Voila! Car fired on the first try and has been operating perfectly ever since. Make sure your points are isolated from the body of the distributor using a continuity meter and that your ignition cable isn't grounding out somewhere inside.

Starting with the basics is a good idea--fresh points & condenser and clean electrical contacts will improve your odds. If the Buick is like the Model A (I'm sure they operate on the same principles, anyway), I believe you can check for spark by holding the distributor end of coil wire near the block and manually opening the points with a screwdriver. When they open, it should generate a spark you can see between the wire and the block. That's an easy trick I learned from <span style="font-weight: bold">Model A Hal</span> that made troubleshooting a lot easier--no cranking and holding a spark plug at the same time. You can work backwards from the points, but I would start there.

Hope this helps. I know it can be frustrating--electrical problems are the worst! Let me know if there's anything I can do to help.

[Charles2]

I've found that cars that have been stored for a long time accumulate crud on the ignition points and this prevents sparking. Clean the contact surfaces with mineral spirits, then alcohol and finally, get some #400 sandpaper and polish the contact surfaces. Most of the time, if the car was running when it was put away, this will resurect the ignition system enough to get it running again. Good luck!

[Pete O]

To figure this out, you really need be systematic. Follow the whole circuit with a voltmeter from start to ground, testing the voltage at every connection. The problem could be anywhere along the way, including the ignition switch.

Pete

[Guest strait8]

Jump a wire directly from the battery,this will bypass the ign. sw. and lead to the coil.With the dist.cap off see if your points open and close if so and they are clean you should get a spark from th center coil wire to ground assuming you coil is grounded.A shorted capacitor will kill your ignition and an open one will reduce it because for a good spark a correct value capacitor along with your primary coil winding create a resonant circuit which greatly increases the spark .a 12 v test lanp will quicky show a lack of voltage even on 6volt circuits amd a couple of jumper 16ga.leads with alligator clips will make you job easier.

[Garyr1016]

Update 4-27-05 pm

It runs!!!! I replaced the coil and the coil wire to the distributor, and the engine started on the first try. The car had not run for 20+ years, we all did the happy dance around the garage. After it ran for a bit it smoothed out surprisingly well (still a little stutter, not quite a purr but close) considering the broad range of "dry compression test results (see "compression test results" posted on 4-26-05). Thanks for the advise everyone.

Gary

[Patrick W. Brooks]

Gary: I have done that same dance several times. Doesn't it feel great. Patrick W. Brooks

[Gene Brink]

Congratulations, Gary. Good luck as you proceed...