Model A Ignition Woes--HELP ME, PLEASE! (long)

[Matt Harwood]

OK, I'm going absolutely insane. I just spent 8 hours trying to make a 1930 Model A Ford run. Points and condenser igntion, about four wires, no problem. Here's the story:

Thursday dad calls and asks me to help move the Model A into storage. No problem. Car has just been repaired by local garage who did repairs on ignition system. Car runs great and has run great for several weeks. Driving home, explosive backfire car rolls to a stop, dead. Restarts several moments later, but dies again about two miles down the road. No restart.

I return later with tools, change spark plugs, check cap & rotor, but don't do much of anything. Car starts and runs like a champ back to my house.

Friday morning, no start. No spark at all. Go to Snyder's Antique Auto parts and get new:

<ul style="list-style-type: disc">[*]Coil [*]brass strips AKA spark plug "wires"[*]Distributor body[*]Distributor cap[*]rotor

So I install everything. Still no start, no spark. Now real work must begin. Today I get up early and begin with swapping the old coil back in. Guys at gas station used new-style coil-to-distributor wire, but it checks out OK in terms of continuity. No start. Replace all wiring (ALL wiring). Following diagram in original Ford manual, I replaced the following:

<ul style="list-style-type: disc">[*]Starter to junction block terminal A

[*]Junction block terminal A to Ammeter terminal A

[*]Ammeter terminal B to junction block terminal B

[*]Junction block terminal B to generator

[*]Ignition switch to coil + side (remember, the Model A is a positive ground vehicle)

[*]Small jumper wire from coil (-) side to junction block terminal B

OK, so all the wiring in the ignition system is new and good and in place according to the wiring diagram in the manual.

No dice. I remove plug #1 and ground the electrode to the block to watch for spark as I crank. Car fires on 3 cylinders but dies. Car briefly restarts but dies after I reinstall #1 plug and try again. Then no more spark. As a last resort, I replaced the armored cable from ignition switch to distributor after finding the wire was broken at the distributor. Still no spark, not even an attempt to start.

Now I do continuity tests. All wires are good and have good connections. Switch is good (off=no continuity, on=continuity). Connecting the points in the distributor to the the other end of the armored cable at the ignition switch and I have continuity. Turn switch on and I have continuity in all places leading back to the points, both terminals on the coil, the switch and at the junction block terminals.

Here's where I'm thinking the problem lies: the coil. I don't remember which coil was on the car at the time it sort-of started. The + and (-) terminals of the coil test good for continuity on both coils (this should be the case, right--the + and (-) sides are connected). With ignition on, however, continuity fluctuates between the + and (-) terminals and the points in the distributor--sometimes it is continuous and sometimes it is not. Everything inside the distributor is continuous, which seems wrong, but I can't see a short anywhere. Should the coil be grounded somehow? It is mounted upside-down (terminals facing down), could this be causing problems? I'm out of ideas.

So what the heck else could be wrong?!? Battery has good charge. Wires are all new and sufficiently large gauge. Cap & rotor are new, points are new and properly gapped (condenser was not replaced by gas station guys--perhaps this is the problem (see below)?). New and old coils show same symptoms. I get 6V at the distributor cap coming off the coil with the ignition on.

Here's the weird part. I have this thing called a "no short condenser":

and it clearly seems to fit here:

(red arrow is where it fits, white arrow points to a threaded hole ostensibly to screw it in place).

However, the car ran fine without this part and I don't have a clue what wire screws into the other end of this "no-short" condenser. The armored cable? a wire from the points? I believe there's a condenser already in the distributor connected to the points:

I have noticed that the plate, points and condenser are all connected to each other and show continuity at all locations no matter what I touch. Should the condenser be isolated somehow?

There's also the possibility that my wiring is wrong. I followed the book, but a second image with a photograph of the junction block says that the jumper to the coil (-) should come from the same terminal as the starter. But when I took it apart, it was coming from the same terminal as the generator (they're all connected through the ammeter anyway, right?). Check out the differences:

Here is the wiring diagram:

And here is how it looks in a different book and how the car was set-up when I took it apart (I added color so the wires would match up with those in the wiring diagram above):

Note that the primary difference is the black wire going to the (-) side of the coil. In the wiring diagram, it says that this wire should come from the terminal between the starter and the ammeter (pure yellow wires). But in the image above and the way it was before I took anything apart, this wire was on the terminal between the generator and the ammeter (yellow with black tracer). I tried switching it back and forth between the two terminals as well as switching the + and (-) sides of the coil with no effect. Right now I have the ignition system set up as shown in the photograph, as it was when it was running correctly.

I'm completely at the end of my rope. I've done all the tests the manual says and all parts check out OK, except the coil and condenser, which cannot be tested.

You guys who say the old cars are so simple and easy to fix, I'm counting on you. I'm at a complete loss and am ready to jump in the lake over this. I built my supercharged V8 Ford Ranger pickup with EFI, a supercharger, ABS brakes and A/C and it fired on the first turn of the key and blew ice-cold air the first time I tried. But I can't get a Model A ignition system to work at all. Help me! Is it possible that I have two bad coils (is this even likely--I've never heard of a bad coil, let alone two of them)? Could the condenser be shot (again, I have no idea what it does or how it works or how to test it)?

Thanks very much in advance, and if you live in the Cleveland area and want to come help me fix it, I'll give you anything you want!

[nearchoclatetown]

Matt, I think you are thinking too much. Your picture shows a condensor by the points { I don't know anything about this other condensor under dist.} but I didn't see that you replaced it. Sounds like typical condensor trouble to me.

[Lozierman]

I suspect the real problem is the timing gear is stripped. The gear is made out of a fiber type material and after years of use, or even long storage they sometimes break. The break happens around the core/center, where it attaches to the cam shaft. It is probably able to turn a little as the cam rotates, but it isn't moving as frequently as it should so it is sometimes just turning. but only enough to cause an occasional spark. This same thing happened to one of my dad's Model A's many years ago. We found out what was happening by checking the timing, using the removal screw/plug and found out the timing gear wasn't moving around as it should have been doing. Had to tear the engine apart and replace the timing gear. It ran perfectly after that.

I hope this helps.

Mike Turner

[Matt Harwood]

Hi Guys,

Thanks for the replies. I'm hoping the cam gear is OK because, like an idiot, I pulled the rotor and distributor cam out to check the plate and wire under the distributor that connects to the points. I had to use the screw/pin to reindex it (right after this is when it tried to fire). I also used the starter to bump the distributor and it turned without a problem. But not under load...

Although, now that you mention it, this would explain why it ran right after reindexing, but not for long. It would also explain the huge backfire right before dying. But why would it stop running, then start running again after some simple tinkering?

I'll try reindexing it tomorrow and see if it happens again. The more I think about it, the more likely this seems. Aw, poop...

[Guest Albert]

Check the Yellow wire that goes from the points throught the sheld to the coil, with the points open or a piece of plastic or paper between check for a short to ground, as it may have chafed below the points or inside the sheld with the points open and the ignition on you should also get 6V on both sides of the coil, points closed it should go to Ov. Using a plastic screwdriver try opening the points with the ignition on while the output off the coil is held close to the engine block and check for spark, you should also see a small spark at the points at the same time.

[56Roadmaster]

Matt,

The "no short" condenser you show is the original style condenser and does in fact go in where you illustrate however your car has had the unitized points set installed (basically a modern upgrade) and the condenser is on that plate. Originally the old style plate had a metal strip on the bottom side of the plate which had a screw hole in it which was used to attach the brass end to, a real pain to start sometimes (I had a 31 coupe).

you mention that the points plate and condenser all had continuity, that should be true only with the pionts closed (grounded).

Also to index the points you don't move the distributor body because it has fixed indent for the set screw, you instead use the large screw on the top of the points cam shown clearly in your photo. Loosen the screw and move the cam and retighten.

Which leads to the next suggestion (If in fact your cam gear has NOT failed) check the lobes on the pionts cam, alot of after market cams are "soft" and wear the lobes down some times unevenly or completely off( check the points gap at each lobe, if this is the case try to get an original Ford part. Also it could be that the screw mentioned is not tight or (1) the cam has lost the serated edge on the bottom (helps it grip the distributor shaft) or(2) the screw is bottoming out before the cam is tight (there should be a washer under the screw head) That would allow the cam to slip on the shaft.

Finally follow the retiming procedure in a Ford book using the timing pin and setting the cam, and correct gap.

[Matt Harwood]

Thanks for all the feedback guys. I went out there this morning (Sunday) and tried the following:

<ul style="list-style-type: disc">[*]Installed new condenser (purchased from local auto parts store today)

[*]Checked that rotor was moving as it should--yes, rotor is exactly where I left it yesterday, so this <span style="font-style: italic">might</span> rule out the broken timing gear theory

[*]Checked all grounds

[*]Checked all areas inside distributor for continuity with points open and separated by a piece of plastic--no change, all areas still in contact with one another (plate, condenser housing, points, distributor cam all had continuity regardless of points open or closed)

[*]Checked distributor cam lobes--all are sharp and clean

[*]Checked top screw to make sure distirbutor cam is not moving or rotating on distributor shaft. Everything is tight and as it should be.

So now what? Take up drinking? Something stronger? (<span style="font-style: italic">Looks like I picked the wrong week to stop sniffing glue. </span>--Lloyd Bridges, <span style="font-weight: bold">"Airplane!"</span> the movie)

This thing is killing me. My concern is the fact that there is continuity among every piece of metal inside the distributor--something is not isolated properly, though I don't know what, if anything. I also lightly pressed the pin into the timing gear hole as I cranked it to verify that the gear was turning, and it was turning as it should. Hopefully, I've ruled out the gear as a possibility, but now I'm doubting everything I've done so far. Maybe the muffler bearings went bad, or the headlight fluid...

But even if the timing gear were broken and slipping, it should still make a spark at the plugs, just at the wrong time, correct? It <span style="font-style: italic">is</span> turning, so it should still trigger a spark that I could see at #1 spark plug when holding the electrode against the block. I have no spark at all. And if the battery has enough juice to turn the starter, it should certainly have enough juice to fire a spark plug.

I still suspect the coil(s), but have no way of knowing what's right or wrong. I also suspect the high-tension wire between the coil and distributor because it doesn't fit right (the gas station hacks made it themselves). However, it fits into both ends and has good contact in the coil and distributor cap.

Any other ideas? I'm stumped. How about a small-block Chevy in there instead? (just kidding!). Of course, there's always the option of throwing more money at it (new distributor, new wiring harness, etc.) so I know it isn't something I did to screw it up.

The killer thing is that it ran perfectly two days ago using all the parts that are in it now! Aaargh!

[56Roadmaster]

Matt,

Your problem is that plate and condeser housing IS GROUNDED something IS shorted out in the distributor or cable. It When the points are open you should only have continuity between the ground side of the points (non-insulated) and everything else. It could be that your armored cable is shorting against (1) inside its housing (2) between the breaker plate and the distributor housing (3)the insulator at the plate is broken (4) it is also possible that the nut/screw at the ignition switch end is shorting against the fuel tank/cowl behind the dash.(5) check the wire from the points going under the plate for bare spots

Remove the armored cable and check to see if the wire has continuity to the sheathing it should NOT, inspect the distributor end it may appear ok and then cause ground when the spring is compressed. With the cable out do your continuity checks on the breaker plates,if you get an open the problem lies with the cable or at the connection, if every side still has continuity with points open, remove the condenser wire, do the checks again, if you get an open then it was the condenser, if not take out the breaker plate and check it, check also for rubbing of insulated parts.

[Matt Harwood]

Scott, I'm right there with you--I was at my niece's birthday party this evening and came to that same realization (once I actually stopped to think about exactly what the points were designed to do). Something is not right inside the distributor and the points opening isn't driving the current to the plugs. Instead, it keeps flowing through the distributor and grounding out. I'm going to take the thing apart tomorrow and track that down. I'll keep you posted.

Thanks again for all the great assistance, guys. I knew that when I got jammed up, this would be the right place to turn for help.

By the way, what, exactly, does the condenser do? I have no clue...

[Guest Hal Davis (MODEL A HAL)]

I'm no electrical expert, but the condenser gives the current some place to go when the points are broken. That allows the magnetic field in the coil to "collapse" quickly resulting in the high voltage spark you are looking for.

I'm betting you have a short somewhere between your upper and lower plates. Make dang sure your wire that runs from the lower plate to the points is not chafed somewhere or that the insulator that insulates it from the lower plate is not cracked. Make sure that the tab on the bottom of the lower plate is not touching anything except the condenser (if you are using the original style condenser) and the wire coming from the armoured cable.

Also, to ease the work when troubleshooting the system, you can put the distributor end of the coil wire 1/8" or so from any ground and break the points by hand. If everything is in working order, you'll get a spark at the coil wire. No need to reassemble everything until you know you have no shorts. Once you get to that point, you can set your points and timing, etc...

[Matt Harwood]

Hi Guys,

It was a short inside the distributor all along! I took it all apart and reassembled everything carefully and checked continutiy to make sure all was well. <span style="font-weight: bold">Hal,</span> that trick of opening the points and looking for spark at the high tension wire was an excellent tip--thank you! Car runs like a champ; I just got back from a 45-minute cruise around the neighborhood and it runs as well as ever. I want to rebuild the carburetor tomorrow, but with it running so well, I don't want to tempt fate!

Again, big thanks to all of you--you kept me from going insane. This only proves that car guys are the most helpful guys around. Much obliged--and if you're ever in my neighborhood, stop by--there's a free steak for each of you!

[c260b]

For some reason on my 31 model a the distributor isn't settling down as far as i'd like it to. There is a small pin on the distributor housing that is only partially going into the head. Is there some magic to getting the distributor shaft to go all the way down?

[Guest Hal Davis (MODEL A HAL)]

First, I'd check the obvious. Is the hole in the head or the pin rusted up, dinged, damaged, etc... No trash under the distributor body....

If that doesn't fix it, check to be sure the shafts are aligned properly with each other. I have actually gotten them to assemble 180 degrees out. It was probably the inferior repro parts, but even though the "blade" is offset to one side they went together and the car ran. The distributor was like you said, didn't go all the way down, and it wobbled when the engine was running.