Car would not restart

[Kenjt]

My mechanic fixed some issues on my 1931 Model A and then drove it back to my house (about a 20 minute trip). After parking the car in my garage he turned off the engine and we spent a few minutes talking about the work he had done. He wanted to show me something and got in to restart the car - it would not start. He came by the next morning and the car started right up.

Any ideas about why this could have happened?

P.S. My mechanic thinks it could have been the distributor overheating, causing a short.

[Will N]

Could be any number of things. It might be your ignition switch is on its way out, and it wasn't making good contact when it wouldn't start, but the next day when you turned it on it made good contact. It might be the wire connecting the upper and lower plate in the distributor. Could be the insulation is cracked. When you moved the spark advance lever to restart it the day it wouldn't start, it shorted out. But the next day if you moved the lever it might have moved the wire so the short was removed.

[katy]

Possible poor capacitor.

[Kenjt]

Originally Posted by Will N

Could be any number of things. It might be your ignition switch is on its way out, and it wasn't making good contact when it wouldn't start, but the next day when you turned it on it made good contact. It might be the wire connecting the upper and lower plate in the distributor. Could be the insulation is cracked. When you moved the spark advance lever to restart it the day it wouldn't start, it shorted out. But the next day if you moved the lever it might have moved the wire so the short was removed.

Thanks for your quick reply. I don't think it's the ignition switch because it's new and has been working fine. My mechanic is going to take the car back and try to figure out what's going on so I'll let him know your thoughts.

[Ernie Vitucci]

Often this problem is caused by either a Condenser or Coil that is near the end of life. They work when cold and not when hot...Ernie in Arizona

[nkaminar]

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First thing to do is to determine if there is a spark. If not then trace out the ignition system. If there is a spark it could be that the gasoline in the carburetor has vaporized to the point where the car is flooded (mixture too rich to burn). This can happen if the float valve is leaking. To test, open up the throttle wide open and try to start the car. If it is really warm (summer) and my car is stopped while the engine is warm, then I will get a lot of vapor to the point where it is really hard to start. Under these conditions I will turn off the fuel and let the engine run for a while before turning it off. Then start the car with the fuel still off.

[Big hammer]

When I’ve had a hot no start, I’ve pulled the choke and crank it 2-3 turns and it starts. I think that if it’s a vapor lock, pulling the choke and cranking pulls the vapor out unblocking the vapor lock. Coolant temperature 195*F , that problem has been resolved. Using the tools you have with the model A , adjusting timing, adjusting GAV, watching the ammeter wiggle, pulling the choke can help yourself with starting issues.

[Kenjt]

When my mechanic came this morning the car had been sitting for almost 2 full days, in a cold garage. It started right up and he backed it out of the garage and stopped to let a car pass. The engine stopped and and would not crank. We pushed the car back into the garage. He opened the distributor and found no power. However, the horn worked fine. He's convinced it is a problem with the distributor and will try again tomorrow. Hopefully it will run and he can bring it back to his shop.

[eagle]

He opened the distributor and found no power. If the points are closed and ign sw on, there will be no power. Check on the hot side of the coil, should be full battery voltage there all of the time. Check the point side of the coil, when points are open should be full battery, when points are closed and ignition switch is on, should be ground. Use a good voltmeter instead of a test light, it'll give you more accurate readings.

[cr1248]

If you have another spare distributor top cap, make a troubleshooting tool by cutting off both sides of it leaving the part intact where the coil wire goes in and snaps onto the distributor. Snap it back on the distributor and turn the engine over and you will be able to see inside if you have point spark as well as spark between the rotor and cap. This helps determine if it’s an electrical or fuel problem.

[Greg Jones]

Check the lower plate in the distributor. Specifically, check to be sure the contact strip is solid and secure on the lower plate with no loose rivets. If rivets are loose and you can move this strip around, replace the lower plate. Another issue with 31 distributor is how it was "beefed up" to add reinforcement. There are small additional casting reinforcements that stick out further than previous distributors, and repro lower plates may short intermittently against the casting. Probably something simpler, but worth a look....

From Tom Endy: http://www.santaanitaas.org/wp-conte...Repo-Fault.pdf

[katy]

Originally Posted by eagle

[I] Check on the hot side of the coil, should be full battery voltage there all of the time.

Not necessarily, it depends on how the car is wired.

[Will N]

Originally Posted by Kenjt

When my mechanic came this morning the car had been sitting for almost 2 full days, in a cold garage. It started right up and he backed it out of the garage and stopped to let a car pass. The engine stopped and and would not crank. We pushed the car back into the garage. He opened the distributor and found no power. However, the horn worked fine. He's convinced it is a problem with the distributor and will try again tomorrow. Hopefully it will run and he can bring it back to his shop.

In my mind, "would not crank" means that the starter is not turning the engine over. Is this what you meant? Or, was the engine turning over, but it was not firing? If the engine wasn't turning over, you could have a defective starter where some of the soldered connections on the armature are bad and there are dead spots on the commutator. If the starter happens to come to rest on one of these dead spots, it won't turn when the starter switch is engaged. But if it comes to rest on a good segment of the commutator, it will work. If you meant it wouldn't fire, I would still look at the ignition switch or wire connecting the lower plate to the points.



How long did it run before he backed it out of the garage? Long enough for everything to really heat up, or just a short while? When it stalls, does it pop and backfire and run poorly for a little while before it dies, or does it just stop dead like you've turned the key off? If it stops dead, my vote is a bad ignition switch. Even new switches can be bad. If it runs poorly before dying, I'd look for a short in the distributor.


Another thing to look at is fuses. Do you have a fuse in your wiring? A fuse holder with loose connections can cause intermittent electrical problems like you're seeing. The fuse holders that attach to the starter motor have been known to corrode on the underside making bad connections.

[Kenjt]

Originally Posted by Will N

In my mind, "would not crank" means that the starter is not turning the engine over. Is this what you meant? Or, was the engine turning over, but it was not firing? If the engine wasn't turning over, you could have a defective starter where some of the soldered connections on the armature are bad and there are dead spots on the commutator. If the starter happens to come to rest on one of these dead spots, it won't turn when the starter switch is engaged. But if it comes to rest on a good segment of the commutator, it will work. If you meant it wouldn't fire, I would still look at the ignition switch or wire connecting the lower plate to the points.



How long did it run before he backed it out of the garage? Long enough for everything to really heat up, or just a short while? When it stalls, does it pop and backfire and run poorly for a little while before it dies, or does it just stop dead like you've turned the key off? If it stops dead, my vote is a bad ignition switch. Even new switches can be bad. If it runs poorly before dying, I'd look for a short in the distributor.


Another thing to look at is fuses. Do you have a fuse in your wiring? A fuse holder with loose connections can cause intermittent electrical problems like you're seeing. The fuse holders that attach to the starter motor have been known to corrode on the underside making bad connections.

Thank you so much for your detailed reply.

1. Starter was just replaced. Engine did turn but would not fire.
2. Ignition switch was also just replaced. Car has started quickly each time after the switch was replaced.
3. Did not run the car very long before backing out. As I said, the car started right up and sounded fine.
4. No 'pop' or backfire - it just stopped.
5. First thing I did was check the fuse - it was fine. Like I said, the horn blasted just as it should with the wonderful Model A sound.
6. My mechanic is convinced the problem is related to the distributor. He already ordered a replacement just in case but will, of course, check everything related.

Thanks again for your reply.

[katy]

Originally Posted by Kenjt

First thing I did was check the fuse - it was fine.

How did you check it? Eye ball or w/a meter?

What kind of fuse does it have? The small round one by the starter? Or?

Sometimes fuses will look good but have failed inside near the end and cannot be seen by looking at them, they need to be tested w/a meter.

If unsure, replace the fuse w/a known good one.

[nkaminar]

Possible causes: Short in distributor, cable in to far in distributor, bad condensor, bad coil, a loose or oxidized connector in the ignition system, bad fuse.

[J Franklin]

Gasoline, for sure?

[JBill]

I know, I know. It's always the condenser. But this time I think it really is. I didn't see anywhere that it has been replaced. Would not hurt to try a new one.

[Kenjt]

My Model A is doing strange things. It started right up today and everything seemed to be fine. Then, as I pulled into my garage, it died. I began checking the electrical system and could find no problem. Then, suddenly the horn sounded - I wasn't anywhere near it. It appears that the main switch, by the steering column, must be the problem. I have a feeling it was the problem the whole time.

[Rob Doe]

Ken, your previous post is approximately last Christmas, 2021??? You haven't worked on the car in that time, but five days ago, it started and managed to get out of the garage? Then died? And as you walked away, she honked her horn at ya??? What happened with the mechanic that was helping? Never mind, you don't need to answer that last question, he probably got the H outta there figuring shez posessed! LOL

Intermittent issues such as yours need to be diagnosed immediately after they occur. If your car is wired as a Model A and not customized or lacking the Nov, 1929 wiring change, your ammeter should reflect the Henry Jiggle when you step on the starter, key on.

Here is a logical starting point for an immediate step when your car won't fire off and run. I copied it from my own notes.

I watch the ammeter as my toe pushes the starter button (key on). If I see the ammeter twitch with each cylinder compression, this is good. The twitch is referred to as the ‘Henry Jiggle’. IMHO, ‘driver’ Model A’s should have the November 1929 Service Bulletin wiring change applied, so the primary ignition circuit function is reflected on the ammeter as a negative twitch at low rpms.

If the jiggle is there, the primary ignition circuit is working as it should. Check the secondary ignition circuit for consistent blue sparks. You can remove the plug straps from the plugs or at the distributor and bend them to leave a 1/4" gap from the terminal. Crank the engine over with the starter and watch for consistent sparking at all four cylinders. Having a helper makes this safer and easier.

Report back your results. Is the jiggle there? Are the sparks there? Did the car start?