No spark condition

[Msaby]

Well I have the "A" cranking properly but I have no spark at the plugs. I did a search on the forum and began reading several posts regarding spark issues. I replaced the condensor only because I had a brand new one handy. I have spark at the coil wire. I did the test where I have the points in the open postion, the ignition key turned on, and "jump" the points to ensure I have a nice spark between the coil wire and ground. I cleaned the points and adjusted the gap but I don't have any spark at the plug. Any help is greatly appreciated.

Thanks
Mike

[jmeckel]

If you have spark when you run the starter at the coil wire, but not at the plugs, make sure the cap and rotor are in good condition, there is a contact on the cap that must contact metal tab on the rotor. If that is good, then check the clearance between the rotor contact and the contacts that go to each plug.

Also make sure that the rotor is good, it has a tab that must fit down into the notch in the top of the dist. cam, or it will not turn.

[Mitch//pa]

when you ck the spark make sure its a nice blue with some zap. a weak yellow won't make it to the elctrode on the plugs.
just recently had a weak spark and was able to hold the plug wire with my bare hand. didnt feel a thing

[Tom Wesenberg]

Did you forget to install the rotor? I did that one time and saw a couple others also do it.

I've also seen rotors go bad where the spark travels right through to the shaft.

[Msaby]

The distributor cap and rotor were replaced a few years ago, they still look like they are in great shape. The rotor is down all they. I am pretty sure I did have the rotor installed when I checked for spark but I will double check these things though tomorrow to make sure I didn't miss them.

The spark I thought might be a little weak but it does appear to be blue in color. If I do have weak spark what should I be looking at?

Thanks
Mike

[Tom Wesenberg]

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A weak spark could be caused by a poor condenser or coil, but I'd try the condenser first. Changing the stock condenser is very quick and easy if you follow these steps exactly:
1. Lay the new condenser next to the distributor.
2. Remove the ground screw first, then walk to the drivers's side.
3. Remove the terminal screw and while keeping light pressure on the screw, slip the old condenser out and the new condenser in, and tighten the terminal screw.
4. Go to the passenger side and install the ground screw. Done and easy!

[Msaby]

I actually did change out the condensor today.

Thanks
Mike

[Chuck Sea/Tac]

I had a 12 V system the other day that had a spark, weak looking to me, so we stuck a new coil on it. The spark looked the same to me, but she started up and ran. Before it would only run for a few seconds, then die and not start again until it rested for a while.

[BILL WILLIAMSON]

Msaby,
IF the spark shorts through the rotor, it usually leaves a rainbow looking discoloration up inside the rotor hole where it fits on the shaft. Look at it outside in the bright sunlight. Or hold the coil wire close to the steel contact on top of the rotor & crank it over. A slight THIN spark might show, but if it is a good SHARP snap, then the rotor's gone KAPOOIE! With every tune up, REPLACE the rotor, & throw the old one AWAY! They're CHEAP. (Me Too!) Bill W.

[1931 flamingo]

Is the rotor turning??
Paul in CT

[Msaby]

Yes the rotor is turning when I crank the engine.

[31 A4door]

If you have spark at the coil wire but not after the cap then it can only be 2 things.
1] is the rotor is no good and is passing electricity through it and shorting to the dist shaft.

2] It is so far out of time that the rotor does not line up with the post to the plug.

Check the second first by using the coil wire. turn on ignition and rotate engine by hand until it sparks at the wire. then turn off ignition and put the cap and rotor on... Does the rotor line up the the post? If it does then it has to be the rotor.

Jerry

[roccaas]

Are you sure that you have the coil properly wired? Reverse the + and - and you'll still get a spark off of the coil wire, but it will be weak (often yellow instead of a loud snapping blue).

[Msaby]

When I get to the garage today I am going to check the rotor. I don't think the coil is wired incorrectly since the car had been running all these years but I will still check it to verify it.

Thanks
Mike

[marc hildebrant]

Originally Posted by Tom Wesenberg

A weak spark could be caused by a poor condenser or coil, but I'd try the condenser first. Changing the stock condenser is very quick and easy if you follow these steps exactly:
1. Lay the new condenser next to the distributor.
2. Remove the ground screw first, then walk to the drivers's side.
3. Remove the terminal screw and while keeping light pressure on the screw, slip the old condenser out and the new condenser in, and tighten the terminal screw.
4. Go to the passenger side and install the ground screw. Done and easy!

Tom,

With regards to #3, how do you keep pressure on the screw if you remove it?

Marc

[Mitch//pa]

Originally Posted by marc hildebrant

Tom,

With regards to #3, how do you keep pressure on the screw if you remove it?

Marc

the screw on the drivers side you hold pressure with the screwdriver and do not remove it.
just slide in the new cond and tighten back up

[Jim/GA]

Look at the height of the little flexible tab on the top of the rotor. Make sure it is tall enough to make contact with the underside button of the distributor cap.

Take an old distributor cap and cut two sides off of it so that you are left with a narrow strip that goes across the top of the distributor body and is held on by the 2 spring clips. It has the button in the middle and a place ot put the coil wire. Put your coil wire in that. Crank the engine in a dark area and look for sparks inside the distributor body. The A engine will actually run with this setup. Very helpful for diagnosis.

[Tom Wesenberg]

Actually the coil has the same output with either polarity, but the spark plug fires easier if the hot center electrode is negative. Here's an excellent short read all about polarity:

http://www.chicagolandmgclub.com/tec...neral/574.html

[heneste]

Jim makes a good point about checking the distributor when the cap is partially exposed. This will allow you to see whether or not the rotor is trying to spark to the contacts on the distributor body. It could be that the distributor cap to rotor gap is too much from wear.

The image shows what Jim was suggesting.

[Msaby]

Wow that's a great idea. I am going to the garage now and begin testing.

Thanks
Mike

[Tom Endy]

If you have a spark coming out of the secondary wire from the coil and the rotor is turning, I would suspect either the rotor or the cap. They can both develop a hidden crack that when a spark shows up it goes straight to ground. I would substitute another rotor and cap and see what happens.

A friend has a rotor he keeps for show and tell. It looks perfectly functional. You can check it with an ohm meter and it has continuity. Put it in a distributor and it will not work. It apparently has a hair line crack that is not visible from the center connection through to where it sits on the distributor shaft.

Tom Endy

[Msaby]

Okay I have spark at the plugs now. I thought about what Tom said when he asked did I install the rotor. We all know sometimes we get caught up with troubleshooting and miss the details. I put everything back together and started retesting everything per all the suggestions in this thread. I believe now it is in fact the rotor. I examined it and it appeared to have some moisture as well as some carbon tracks on it. I washed it off with carb cleaner and retested for spark at the plugs. I do have spark now.

On another note regarding spark when I did retest the coil wire, I was unable to get spark if I held the wire 1/4" from ground. I had to hold it more like an 1/8" to see it arc. Maybe a weak coil?? The spark also seemed intermittent. When I stopped cranking the engine it always seemed to throw a nice arc then, timing maybe?. I sprayed the carb with a little starting fluid just to see if it would ignite. It wouldn't try to start until I stopped cranking it then it sputtered briefly

My question here is should I replace the coil or because I now have spark at the plugs I should consider it okay at this point and begin looking at timing the engine correctly.
I do plan on purchasing a new cap, rotor, condensor, and points.

I do want to thank everyone for your assistance, I really appreciate all of your help.

Mike

[Bob C]

When I stopped cranking the engine it always seemed to throw a nice arc then,

I would check the voltage while cranking, maybe a bad connection or high starter draw causing
low system voltage and the weak spark while cranking.

Bob

[Jim/GA]

Originally Posted by Bob C

When I stopped cranking the engine it always seemed to throw a nice arc then,

I would check the voltage while cranking, maybe a bad connection or high starter draw causing
low system voltage and the weak spark while cranking.

Bob

^^^
| | |

I agree. Read it right at the coil post.

I assume the car is still 6 volts. This is one of the drawbacks to 6 volts. All the connections need to be really clean and tight or you lose too many volts when cranking and you get a weak spark.

Double-check the polarity of the coil while you are there. If you are still positive ground, the wire coming off the positive post of the coil needs to be the one that makes its way down to the points.

The coil may be going out. I always assumed that when a coil failed, you got not spark. Hah! I learned on the Blue Ridge Parkway Tour recently (not my car, a friend's) that the coil will just start giving a weak spark, skip the spark on a cylinder now an then, just give you really poor power. With a new coil it is like a new car again.

[Tom Wesenberg]

I agree with Bob.
Also you should just try hand cranking it and it might fire right off without the starter drain.
It sounds like the points could be dirty. If you start it by hand cranking, and let it run for a few minutes, the points will probably be OK.

[Msaby]

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The car is still 6 volts with a positive ground. I cleaned all the battery terminal connections, cleaned the battery cable to frame connection, cleaned the connections at the starter motor. The wires to the coil do look a little rough but they do have continuity.

High starter draw, are you suggesting I may still have a starter issue?

To test for cranking voltage, you want me to measure on the positive post on the coil and ground. What voltage is acceptable during cranking?
Thanks
Mike

[Tom Wesenberg]

You'd have to measure on the coil negative post and a good ground (which is +).
While cranking, the coil should still get about 5 volts.

[Msaby]

Okay here is what i have for voltages.

Voltage at the battery 6.38 this is a new battery
Voltage at the coil 6.37
Voltage at the coil while cranking 4.77-4.80 measure from the negative post on the coil.

The negative side of the coil has a short wire which terminates on the stud on the drivers side of the terminal block. The positive side of the coil has a wire which runs up into the dash.

My first question I guess I need to ask is the coil wired properly?

The voltage dropped under 5 volts at the coil during cranking. Does this mean I should begin looking at the starter being a problem?

Thanks
Mike

[Tom Wesenberg]

From what you describe, the coil is wired correctly.
I'll have to check my voltage the next time I crank the engine, but 4.8 seems like it should work OK to start the engine.
Have you tried hand cranking it to fire it up?

[Msaby]

Hand cranking isn't an option for me.

Thanks
Mike

[Tom Wesenberg]

Originally Posted by Msaby

Hand cranking isn't an option for me.

Thanks
Mike

Can you get someone to hand crank it?
Twice over the years I had to hand crank mine after it sat for months in damp weather. Once it ran for a minute, the points worked good and the electric starter could then be used.

[Msaby]

Tom, I placed an order yesterday for parts. I order a new dist body, top, rotor, condensor, points set, coil, coil wire, coil wiring, and battery cables. This should rule all these items out. I will have to see then if I can find someone to hand crank the engine for me.

I drained the fuel tank yesterday. I hope to refill it this weekend so it has fresh fuel for start up when my parts arrive.

Thanks
Mike

[Msaby]

If you think the starter may be still causing issues because of the marginal voltages I will gladly try and have mine rebuilt. I am very determined to get this car running.

[Jim/GA]

No. You have enough voltage at the coil to start. If the starter turns the engine over, you are good.

Now that you know you have spark at the plugs, try giving it a shot of starting ether in the carb air inlet instead of choking it.

[Msaby]

Update....She is now running! I typed a long post on the things I did to finally get it running but when I went to post, it disappeared. Here is the short version.

I found several items that may have caused my problem. I think the biggest issue was the wires on the terminal block were actually reversed. I couldn't believe it, I had to confirm with several resources that the wires were actually reversed. This car has been in my family for many years and had been running for most of them so I was very skeptical of these wires being backwards. I did find a few other issues that I had to address but I am just glad it is now running. It starts everytime with just a quick tap of the starter.

The sad news is the waterpump seized. I will start a new thread regarding the water pump. I really just wanted to update everyone as well as thank everyone who offered such great advice and for being patient with me.

Thanks
Mike