No spark at the plugs

[Daba]

1930 Truck
No spark at the plugs ? I have spark at the points, I have power coming out of the coil to the top of the distributor. But nothing at the plug. I have changed the distributor I have changed the distributor cap rotor and body I have changed to all new wiring and still nothing at the points? any help would be fantastic thank you Daba

[ndnchf]

At first you say you "have spark at the points". Then at the end you say "still nothing at the points". Which is it?

Check that you have .025" rotor to cap contact gap and be sure the tab on top of the rotor is bent up enough to make good contact with the center high tension lead contact.

[nkaminar]

I think ndnchf meant to ask if no spark at PLUGS or at POINTS. Big difference.

[nkaminar]

1. Do you get a spark at the end of the high tension wire coming from the coil when you short the open points with a screw driver?

2. What is the voltage at the points when they are closed and when they are open with the ignition on?

3. When you say no spark at the plugs, is it one plug or all plugs? Have you arranged the straps coming from the distributor body to the plugs so that there is a small gap (1/4 inch) either at the distributor body or the plugs so that you can see if there are sparks at all four plugs?

4. Is the high tension wire inserted all the way into the coil and distributor cap?

5. Is your truck green?

[Daba]

Sorry but I meant no spark at the plugs. It just started snowing here like a blizzard so I’ll have to get back to you on your suggestions. Thanks again and I’ll get back to you soon.
Daba

[Daba]

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I just went out and braved the snow and there is a lot of spark coming out of the end of the distributor cap from the coil when I ground out the points. I pulled out the plugs spun the motor over and still no spark coming from the plugs. I don’t have a volt meter only a test light.

[edzaha]

Did you ground the plugs when you tested them?

[Daba]

They were sitting on the head so I assumed they were grounded.

[Daba]

Also as my grandson was turning it over I put my test light on the top of the distributor output post for the plugs and got nothing.

[ndnchf]

Originally Posted by Daba

I just went out and braved the snow and there is a lot of spark coming out of the end of the distributor cap from the coil when I ground out the points. I pulled out the plugs spun the motor over and still no spark coming from the plugs. I don’t have a volt meter only a test light.

Not sure I'm following you. So you have good high voltage coming from the coil to the center of the distributor cap, but not out to the plugs? If so, did you check the rotor to distributor body contact gap? it should be .025". If it's too large, the spark can't jump the gap. Also, is the rotor center tab reaching the cap's center contact? it may need to be bent up a little.

[Daba]

I did not check the gap but that will be my next move I have been using used parts not new I have some old stuff here that I’ve been changing out I will go back to the original configuration with cap rotor and body to see if that makes a difference and I will measure the gap.
To me if I have power coming in the top of the distributor cap from the coil and power at the points it should fire But I thought I may have missed something. I’ll send a update soon.
Thanks again

[Y-Blockhead]

Sounds like you have lightening going into the distributor but not coming out and going to the sparklers. Look for traces of carbon tracking inside (and outside) the distributor and rotor. It will cause an easy path to ground.

[1crosscut]

Are you using an original style rotor body and cap?

Pull the coil wire out of the distributor, hold it an 1/8" or so away from a clean head stud/nut, open and close your points with a finger nail or stick. You should see a fat blue spark jump the gap.

Let us know what you see.

[Daba]

Unfortunately I’m working outdoors and we are having a blizzard right now good old New England it was 65 a couple days ago and absolutely gorgeous out and today it’s snowing like the dickens. I am using original parts I do have a very clear spark coming out of the coil into the top of the distributor I have not had a chance to measure the gap. I will as soon as the snow calms down maybe in an hour or so I hope.

[Big hammer]

I was once messing around with points gap and cleaning, it was running before and then no spark to the plugs……. Someone forgot to reinstall the rotor, it happens! my defense it was dark and cold lol

[nkaminar]

Daba,

When you get the fat spark out of the high tension lead from the coil are you opening the points or turning the engine over? Or are you shorting across the points with a screw driver? With the points closed and the ignition on do you get an indication of voltage at the points with your test light? With the points closed you should not see any voltage there. Don't leave the ignition on for more than 30 seconds.

I think you said that you changed out the rotor but perhaps it is bad and grounding out somehow. Ditto the distributor cap. If these are used parts, or even bad new parts, there could be a problem there. There have been reports of bad distributor housings too.

Multi meters from the hardware stores are inexpensive and besides giving you voltage will tell you if you have a short. Instructions come with the meter.

[Mulletwagon]

If high voltage is coming to the distro cap but not proceding to the spark plugs, might ensure that the springy contact on top of the rotor is making contact with the center distro cap contact which receives voltage from the coil. If the coil is producing high voltage there is not too much left to break down and stop voltage from getting to the sparkers. If the distro had been removed the gear timing on the cam may be off causing the rotor to try and pass a spark/voltage in between distro cap contacts. Let us know how it goes.

[CT Jack]

You said you changed distributors. When you installed the ignition switch cable into the distributor body did you screw it in all the way? If it is too far into the distributor body it could be making contact causing the points to be grounded. This would prevent the spark plugs from firing.

[nkaminar]

I think Mulletwagon (the real skinny guy with the dark blue sedan) might have hit on the reason the sparks are not getting to the plugs. You can turn the engine over slowly with the hand crank to see where the points are opening. The rotor should be pointed at a contact on the distributor housing when this the points open.

[Jim M]

Some time ago I had the same problem that your are having and it was EXACTLY what CT Jack has described. Took me about a week of frustration to figure it out! (and a few shots of Jack Daniels...lol)

[burner31]

Originally Posted by Jim M

Some time ago I had the same problem that your are having and it was EXACTLY what CT Jack has described. Took me about a week of frustration to figure it out! (and a few shots of Jack Daniels...lol)

Ignition switch cable should be finger tight/snug into the distributor
Some crank it down so tight it grounds and then wonder why it won't start

[Daba]

Absolutely correct I changed the cap rotor and distributor body and that did the trick thanks for all your help. I look forward to needing you again soon.
Daba

[Daba]

Absolutely correct I changed the cap rotor and distributor body and that did the trick thanks for all your help. I look forward to needing you again soon.
Daba

[nkaminar]

As I said in post #16, there have been reports of bad housings. It must be a manufacturing issue or a breakdown of the conductors. Glad you got your truck running.

[ndnchf]

Glad it was something simple!

[Daba]

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So I had it running for a bit a few times. I finally took it for a short ride around my yard. It sputtered a couple times and then BANG backfire and stalled. So I rechecked the timing and now it spins over but won’t pop off ?? Any suggestions. I have spark at the point and spark at the coil wire coming in. It has gas and gav turned 1/4 turn, Maybe it’s flooded not sure. I’ll try again tomorrow.

[nkaminar]

It could be that the distributor jumped timing 180 degrees. This can happen if the shafts are worn and the distributor shaft slips and re seats 180 degrees out. The slots are offset so this doesn't happen unless things are really worn. I did happen to me once many years ago after hitting a bump on the road. The distributor can then jump back so the timing will return to normal. This is an unusual problem so it is likely something else. Backfiring can be caused by a lean mixture. If the fuel flow is restricted the carburetor can run low causing sputtering and backfiring and stalling. If you have an aftermarket filter in the line this can be the cause. Others have reported a similar issue when there was something in the tank that would block the flow intermittently. If the line into the carburetor is pushed too far in at the fitting this can also restrict flow. Restricted fuel flow can also be caused by blocked or missing vent hole in the gas cap.

[Ernie Vitucci]

Good afternoon...The backfire could also be a condenser that is at the end of its life. They are ok cold, they start to fail as they warm up. Don't get a cheep one...get a good one from Bratton's, Arizona Model A, or another of the major suppliers...Ernie in Arizona

[aermotor]

I have had the same problem of no spark at the plugs. After starting over several times with the timing procedure it turned out that the point gap was too large. After setting the gap when I torqued the screws down the points moved and like a dummy I didn't check the point gap after torquing the points down.

John

[The Master Cylinder]

Originally Posted by aermotor

I have had the same problem of no spark at the plugs. After starting over several times with the timing procedure it turned out that the point gap was too large. After setting the gap when I torqued the screws down the points moved and like a dummy I didn't check the point gap after torquing the points down.

John

Are those modern points? I can not see how "torquing the screws" would change the gap on original type points.

[lrf]

On a tour recently, we were on the freeway about 50 mph, pulled off on an offramp and the "A" quit, tested: no spark to plugs. Looked at the distributor cap and the carbon piece was missing from the cap. Replaced the complete distributor and she ran. At the next seminar, the carbon piece was found jammed and grounding the points. These cars are so simple and yet confounding. Love my "A"!

[aermotor]

Originally Posted by The Master Cylinder

Are those modern points? I can not see how "torquing the screws" would change the gap on original type points.

With a lock washer under the screw that is next to the contacts the position of the lock washer digging into the fixed points arm and the screw try to move the arm towards open or close.

[Daba]

I’ve been trying all morning and it won’t pop. I have rechecked the timing and it’s spot on, I have spark at the points (modern) and the coil fires off when I open and close the points. I have great gas flow. I reluctantly tried ether in one of the spark plugs and in the carburetor and still have no bang. it seems to me like it’s a spark problem.

[ndnchf]

All that cranking and fuel into the cylinders may have washed all the oil off the cylinder walls, resulting in a loss of compression. The rings need oil to seal well. I've seen this happen. Try pulling the plugs and add a little oil to each cylinder.

[Daba]

I forgot to mention that it sat for a few years before I started trying to get it going again. But it was starting 4-5 times before I tried to move it around. A when I was going down a slight grade and turning to the left it started to sputter and then pop backfire now it won’t start. I’m confused because I have gas and spark. The last message said to add oil to each cylinder how much would you recommend a couple caps s or so??
Thanks again

[ndnchf]

You don't need a lot of oil. Maybe a teaspoon or 1 squirt from an oil can. Enough to get some oil on the cylinder walls and the rings to help them seal. It'll smoke if it starts, but that will burn off quickly.

[Certimafied]

Im just going to throw a few things out that I have experienced in the past with old vehicles not necessarily model a's.

Be sure your cap can touch the rotor. Be sure the carbon piece is in the distributor top and the rotor top is springy.

Check the gap between your rotor tip and the distributor body.

Check the condition of the electrodes inside the cap and where the plug straps/wires attach. Corrosion will cause high resistance that can cause some funky things.

With the top off the distributor and the rotor still in place on the distributor shaft, hold the high tension coil wire just above the rotor and spin/crank the engine over. Spark should not want to jump to the rotor, if it does the rotor is grounded/Bad.

Pull the cap off the distributor and the rotor off the shaft grab the distributor shaft, give it a forward and backward wiggle there shouldn't be any, or very minimal. My A had too much play and would give an erratic idle and hard start sometime. If this is the case it seems it should still try to pop at some point though.

A Different A I worked on some time ago had the timing rod pop off at the steering column. The issue didnt arise until trying to restart. It looked good initially at the distributor until I looked from the other side. Even if your rod is attached still be sure it is in the correct setting for starting.

My A had a condenser fail once, however that resulted in No spark.

There is a possibility maybe that your high tension coil wire is faulty. In situation it has a break in it but when you hold it for testing it works. If you have a multimeter you could check the resistance of that wire. Solid core wire should have minimal resistance.

I had a weird thing once on a car where the coil had a break in it at the nose where the high tension wire plugged in and the spark would jump to one of the primary posts of the coil instead of go down the wire. You can see that in the dark pretty clear usually. you may even hear the pop from the spark.

Be sure your plugs are dry and clean, may as well check the gap while your there too.

Good luck with everything! I can understand your struggles with the cold, fingers just don't like to work under a certain temperature!

[nkaminar]

Daba, The bottom line is that you must have sparks at the plugs at the right time. Take the plugs out and lay them on the head. Leave them hooked up to the distributor. Pull the timing lever all the way up. Turn the ignition on and hand crank the engine over slowly. Each plug should fire as its piston gets to the top. You can know when the piston is at the top of the compression stroke by sensing the compression with your thumb in the spark plug hole while someone else cranks. Once you sense the compression on one cylinder you can just use the timing sequence (firing order) to know when the other pistons are at top dead center. The timing sequence is 1-2-4-3.

Ndnchf was alluding to a lack of compression. You can test the compression by hand cranking the engine over. There should be resistance on all 4 cylinders as they come up on compression.

[Rob Doe]

I just read through this entire thread, and I know you said the timing is spot on, but there have been threads on here where it turned out to not be correct for various reasons.

When you remove the timing pin and find the detent in the cam, is the piston at top dead center of the #1 cylinder. You can see this by looking through the spark plug hole.

If you then stand on the right side of the car, looking down at the distributor, is the rotor aimed at the #1 distributor body electrode/contact/terminal? The rotor should be aimed approximately at the right front headlight.

The spark/advance/retard lever must be all the way at the top when you are setting the timing. You can't see its position in this photo, but under the left side of the distributor body, the lever should be all the way toward you in the opening of the distributor body.

[Daba]

As I said earlier this truck was sitting for years before I got it. That being said I just added fuel and never looked in the tank after scratching my head for a few days I drained the tank and found water and crud. After cleaning out the tank and carb bowl if started right up. I apologize for my stupidity and appreciate all your help. This place is a wealth of knowledge and would be lost without it.
Thanks Daba

[ndnchf]

Glad to hear you got it taken care of!

[Daba]

Unfortunately it only ran for a few minutes. Since than I’ve reset the timing changed the cap rotor and body, spark plugs and head gasket, changed the fuel and I am still having the same problem it won’t pop I have spark at the plugs and fuel in the cylinders still nothing? It’s driving me crazy. Fortunately it’s a short drive

[Bob C]

Is your rotor in the position that Rob shows in post #39 when #1 is a TDC?

[nkaminar]

Daba, Every engine runs on first principles. Did you do the check that I recommended in post 38? The position of the rotor and the timing are all to make sure that the plugs fire at the right time. There can be a number of things out of adjustment that may look right but not provide the correct timing according to the first principles.

Look in the cylinders or use a wooden stick to sense when the pistons are at TDC.

[Daba]

I just tried to add oil in the cylinders again 2 capfuls cranked it over, have good suction and blow back start and stop for about one minute without putting stress on the starter reinserted the plugs and have the same problems no pop? I torced the head gasket down to 55 pounds and three successions

[Daba]

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Yes it’s exactly as the picture shows. I pulled out the plug I can visually see the piston is at the top and the pin is in the hole. Timing advance lever is all the way up I bought the nu- wrench to do the timing and it points right at number four and the rotor is pointing at number one as in the photo. Also when I changed the head gasket I can visually see everything looks very clean in there the valves are operating properly there was some black scale on the head around the plug which I cleaned off before I reinstalled it. I’m confident I’m doing everything right I must be missing something blatantly obvious.

[abachman3]

Change the wire from the battery to the starter. Make sure that you are using a heavy gauge wire, not a thin one for a 12 volt (modern) system.