Still won't start
 

Still trying to figure out why the car won't start. The car use to start great and run fine until one it started to run rough. Since then when I start the car it run rough for a few seconds then die.
Took apart the carb, clean everything, make sure gas gets into the carb, adjusted the float. No change.
Double check the wiring, seems to be fine but for one thing. Following Jack Bahm troubleshooting procedure. I checked both side of the coil with ignition off and I get both side of the coil hot. Then closed the point, turn the ignition on, and Jack said the the passenger side (witch is the + side off th coil) should be hot, and the other side not, however I have the opposite, the negative side is hot and not the positive. Everything seems to be wired properly???

Then another issue seems to be the distributor. I get no spark on cylinder #1, #2, #3, #4 get sparks.
Bad distributor body? Doesn't seem to be cracked.

Any ideas and suggestions would be greatly appreciated.

Re: Still won't start
 

cannot tell from your wording which cyls have spark and which don't. But when you figure out how to get spark to all 4 the car will run again. The wiring to the coil I am sure has not changed since before when it ran fine.

who is Jack Baum?

Re: Still won't start
 

Just before it started messing with you did you do anything with the battery?

Re: Still won't start
 

As I understand what you are saying you didn't do anything before it started running badly. I would try switching the condenser (you should carry an extra under the seat anyway, if you don't have one buy one). When you buy the condenser get the best one from a place like Bratton's or A&L. Are you trying to say #1 gets no spark and #2, #3 and #4 get spark? It should run on 3 cylinders, but not very well. As far as the distributor caps go, there is some real junk out there in the repro world.

Charlie Stephens

Re: Still won't start
 

Battery positive ground, the black coil wire should have 6 volts at all times and go to the coil - primary post. The red wire should go from the coil + post to the switch, then down to the points. In late 1929 the coil terminals changed sides for polarity. Don't worry about the coil polarity for now, because it will run either way.

Do you get any sparks from the coil wire to the head nut? If not, stop the engine with the points open and key ON, then short the points contacts with a screwdriver, off and on, and see if you get a spark out of the coil wire.

Once you get sparks from the coil wire, then check the rotor and cap. I've seen a couple rotors that shorted the high voltage through the plastic to the distributor cam, so it never reached the tip of the rotor.

Re: Still won't start
 

The way I read your post is you get no spark on #1 but do get it on #'s 2,3 & 4. If that is so, I think it unlikely to be the rotor button causing the problem as it would leak the spark on all cylinders. I suggest you check for spark at the lead from the coil to the distributor cap as Tom says and if you get spark reliably, it could be a faulty distributor cap leaking the spark to ground on #1 but even then, it should keep running, though roughly so long as you have a little throttle on. If you have no throttle on, it may stop as you describe. Have you checked the porcelain insulation on #1 plug for cracks? Spark might go to ground there too.
You say you have gone through the carby so it seems to me that the problem is most likely electrical.

Re: Still won't start
 

Im havin the same problem, how to yu check for spark?

Re: Still won't start
 

i think its no spark on 1,2,3, but gets it on 4:confused:
either way it could be a dist body possibly

how are you checking for spark?

Re: Still won't start
 

I,m sure you checked the point gap.

Re: Still won't start
 

"Im havin the same problem, how to yu check for spark?"

see #5

Re: Still won't start
 

I lean toward bad dist. body, or possibly bad lobe on the dist. cam, causing the points to break unevenly. Maybe a bad pigtail. Maybe a loose condenser. Something in the distributor, though. Easy to check.

Re: Still won't start
 

When you're checking for sparks, not just any ol' spark will do. You need a fat blue-white spark!

Make sure the engine is in a position where the points are closed. Turn on the ignition. Disconnect the coil wire from the dist. and hold the end just removed about 1/4 inch away from a head nut. Using a screwdriver or some other insulated tool, open the points. A fat blue-white spark should jump from the coil wire to the head nut if everything is healthy.

A thin yellowish spark is weak and is no good and of course no spark is most certainly no good.

Allow the points to snap closed if you want to repeat the process for another look.


If the gap is correct on your points I bet they are just oxidized and need cleaning. Points do that just from exposure to the air in the atmosphere. That's why it's best for people to go to the trouble to make sure the engine is in the correct position for the points to be closed when storing a car that will not be run for a long time.

It's also possible that your points may be pitted and burnt and several other things may be the cause of your problem as have already been mentioned. Come back for more instruction if you can't get it going.

Re: Still won't start
 

You forgot to mention to hold the coil wire with an insulated tool (or maybe your computer adjusted your punctuation). Of course he probably would have figured that out pretty quick. You probably don't need the insulated tool for the points as they are only 6 volts.

Charlie Stephens

Re: Still won't start
 

Is the rotor turning??
Paul in CT

Re: Still won't start
 

I don't like to use my fingers when fooling around with sparks and generally wear a pair of good gloves even to hold a coil wire by the insulation.

There used to be a mechanic at a shop here locally years ago who would check for spark, on any vehicle, by holding on to the end of the coil wire while the engine was turning over with the ignition on. If he wasn't satisfied by the amount of shock he received he considered the spark to be weak!

Re: Still won't start
 

To answer some of the questios, the rotor does turn, I get a spark from the distributor cap to the head nut. I took the copper wire off the spark plug (new spark plugs, champion w16) and I have spark on 2,3,4 but not on one ( closest to radiator)

I will order a condensor and both plates in the distributor. By the way the copper end of the condensor where the screws that holds it, spins. Probably should't but I am not sure if it is defective. Should I use a upper plate with the modern condensor?

Lastly what would cause the negative side off the coil to be hot when the point are closed and the ignition on?

Re: Still won't start
 

Do you get a consistent spark from the coil wire to a head nut every time your work the points? If so what does it look like?

Re: Still won't start
 

By the way the copper end of the condensor where the screws that holds it, spins.

That is not a good thing, you need to replace it. But if you get a good blue spark on 2,3,4 you have points that are not opening on one cylinder, or you got a bad dist body. Need to check play in dist shaft, make sure the points are opening on all 4 cam positions.

Re: Still won't start
 

I will check if the point open on all 4 side of the cam. I did not check I assumed that all 4 sides of the cam should be the same. By the way the shaft does not have any side to side play.
Also I was wondering how snug should the rotor fit. Mine is pretty wobbly and I wonder if it is not rotating properly and does not make a spark with the contact for cylinder #1

Re: Still won't start
 

Re: Still won't start
 

No it should not be loose on the shaft. Just a good slip fit. You might put the body on and check the gap between rotor and cap in all 4 positions. Should be around .025 .

Re: Still won't start
 

Flicking the points with a screwdriver may give you a false indication, as you may be covering up a bad or dirty set of points.

Just unclip the brass leads at the dizzy cap and move them about 1/8th inch away from terminal on cap.

Wind motor over, you should see a fat spark jumping across each gap.

This will prove spark as far as the plugs without dismantling anything.

Re: Still won't start
 

How would you cover up the points if the blade was not in between the points?

Re: Still won't start
 

The condenser is shot if the terminal spins. Be sure to use the insulating washer under the head of the terminal screw, or the screw may bottom out and turn the terminal instead of tightening on the strap.

When the points are closed and the key is on, you have about 4 amps going through the coil and that will heat it up. If it still heats up with the points open or the key off, then you have a problem, such as the ignition switch terminal touching the gas tank.

Re: Still won't start
 

the condenser screw should not spin so take toms advice and change it and use the fiber washer under the screw head...

so you say no spark to #1 ok that should not be but with having spark to 2,3,4
the engine should still run but with a miss.... did you try bringing it to TDC with the timing pin and make sure your rotor is pointing to #1? maybe the dist cam slipped position or there is a timing gear issue and it jumped.
maybe the spark is crossfiring in the dist body
some food for thought

Re: Still won't start
 

If the points have dirty contacts and give no spark on their own, using a screwdriver can give a spark if all else is good.

The screwdriver makes the contact . not the points.

The actual correct way is the have the points closed and flick them open with a non conductive object.

Re: Still won't start
 

Yes, I can see that. I use a screwdriver but I watch how I use it. Works fine.

Re: Still won't start
 

Check out the gap between the rotor and distributor body. If they are all the same swap out the distributor body.

Even with 1 cylinder not firing your engine should still run without quitting. The Gordon compressor runs with only 2 and there is a video that has a cut away engine running on one.

Re: Still won't start
 

I'm too lazy to back to the first thread about this so let me ask how do you know you are getting fuel?

Get a can of starter fluid and spray it into the carb. As it dies spray it again and see if you can keep it running with the spray can.

Re: Still won't start
 

One of the most difficult tasks always appears to be to try to help by "guessing" at an "unseen" very "simple" mechanical/fuel/electrical Model A problem from miles away.

Not trying to be funny; but just in case you are getting frustrated trying so many different "things", I would bet (2) fully loaded boxcars full of Model A "Whitewall" tires that a real good senior, grey haired local lawn mower mechanic could locate the problem & advise you of your problem in a jiffy.

Not everybody has a good Model A mechanic close by; but real good "senior" lawn mower mechanics are everywhere.

Realize this is not a response heard of often, but just hopes this can help to get you back on the highway with smiles ........ plus learn a little about the basics of non-computerized engine diagnostics.

Re: Still won't start
 

That's ONLY true if you are trying to show the ignition system is OK.

By stopping the engine with the points open, then shorting with a screwdriver I am showing the points need to be cleaned. This is for a no spark or poor spark condition, which is why the check is taking place most times.

Re: Still won't start
 

Thank you all for all the suggestions. Just to recap.
The battery seems to be fine.
The wiring seems to be correct.
The coil sends a spark to the distributor (will double check for the strength of the spark and color). However when the ignition is on and the point are close the negative side of the coil is hot. (should be the positive side) Not sure why.
The rotor turn and the gap to the contact is 0.25. However it wobble. It should rest on the cam right, but it seems that it is not resting flat. The cam screw slot has some burs maybe it does not allow the rotor to seat flat.
The point gap have been sanded lightly and adjusted to 0.18.
The distributor contact have been sanded lightly and have been check for continuity and they all checked out. Found a crack on the body near the external contact that goes to cylinder #4.
The inside of the distributor is a little rough and hold the body (metal part exposed once I removed both upper and lower plate) is a little rusty. Can I just sand it?
The condenser copper end spins (where the screws attach to it through the bottom plate)

So I am ordering a bunch of parts to replace the coil, the distributor cap, body, both plate, the points and the condenser.

While I am waiting for the parts. I have one more questions. What would be the symptom if the distributor condenser is not working properly? And still trying to figure out the coil issue.

Re: Still won't start
 

If your system is positive ground then the negative (-) side of the
coil should be hot all the time as the black wire comes from the battery.

Bob

Re: Still won't start
 

if the condensor is failing you will have erratic spark or no spark. gotta have a good condenser. points ignition system is an LC circuit and all components must be in tip-top shape

Re: Still won't start
 

When the condenser is bad the engine will miss out, buck and backfire. In other words as has already been said, weak or poor or no spark.

Two tests can be made on the condenser:

Using a piece of wire touching the center or output of the condenser, charge up the condenser by touching the condenser's case to the positive side of the battery and the piece of wire to the negative battery terminal. Allow the condenser to charge for a few seconds, then quickly disconnect and lightly touch the wire to the condenser case. If you observe a spark as the wire gets right near the case, you may assume that the condenser is OK.

You can also check a condenser with a condenser tester to measure capacity. Capacitance should be 0.3 microfarads. Also, using an ohmmeter measure the resistance between the wire or center and the case which should not be less than say 5 million ohms

Re: Still won't start
 

The condenser by Ford spec for the documentation I have should be .20-.25 Microfarads,
In testing a condenser you test for Capacitance, leakage, and resistance. I use an early Ford heyer test set which test for all 3 of these. I would NOT recommend the test stated in a post above to determine a condenser good or not.

As Tom & Mitch said If the terminal is turning it is bad, I would recommend the "Short Proof" condenser and it will probably be the last one you will buy. If you have or know how to use a digital voltmeter I would check the voltage at your coil ( iginition switch off) terminals , should both be 6V+, terminal box studs ( should both be same voltage). If the voltage is lower on one than the other you have a bad connection inside the terminal box or back of the ammeter. If that is good turn on the ignition and with the points open check the voltage at the points, it should be about the same.
If significantly lower you have a bad connection somewhere in the ignition cable or distributor plates.
I gave a seminar last year at the MARC Membership meet on the "voltmeter is the best tool in your toolbox" . When you're having a no start problem it truly is.
If you don
If you don't have one go buy ( or tell your wife you have to have an early birthday present) a decent inexpensive one and start checking voltage to learn and get acquanted. You will always be glad you have it as a tool.

Best of luck... keep the forum posted.
Larry Shepard

Re: Still won't start
 

I'm with Larry. In the end, tho, the only real test of a condenser is, does it work in the circuit it is supposed to be in.

they are dirt cheap. always have a spare

Re: Still won't start
 

Sorry, I disagree. Ford's original spec was .3 microfarads. Also I said that when charging up a condenser and discharging on its case, one may "assume" that the condenser is OK. I didn't say it was guaranteed.

The above method is something that almost any Model Aer can do and requires no test equipment.

Using my equipment I measure condenser capacity and then insulation resistance measured between the condenser center and the case.

The following link shows an original letter from Ford Motor Co. discussing the rating of the Model A condenser.

www.fordgarage.com/pages/condensercapacitance.htm

Re: Still won't start
 

By the way your condenser probably has to long of a screw and it is bottom out. That is why you can turn it. Check that before you have the same thing happen to your new one.

Re: Still won't start
 

Being an electrical engineer of way too many decades experience, I can safely say that the condenser will pass all sorts of tests with meters and such. It will fail actual use tests because the high voltage it is asked to suppress.

Without a tremendously sophisticated rig to observe its dielectric failure - just substitute a good one as mentioned above.

And for those of you thinking the coil only has 6V on the primary, when the points open the primary of the coil rises in voltage till something gives - as evidenced by the arc across the points. The purpose of the condenser (capacitor) is to ensure complete magnetic field collapse. If this does not occur, the coil will magnetically saturate and not be able to build additional magnetic field when current is applied - thus no sparky.

Rate of collapse is controlled by inductance of coil primary and capacitance of condenser - with a ton of Kentucky windage allowable in the actual cap value.

By performing this function, condenser also protects points from excessive pitting - condenser takes the bulk of the current that would otherwise entirely arc across points.



All right - sorry if I am preaching - lost my sister Friday night and guess I need a preacher!