Can't start, no spark getting to plugs

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MoparDart68

MoparDart68

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I've had my car sitting since January, everything worked fine back then. Now, I can't get my car started. It almost wants to fire the first couple of cranks, but never actually does. After more cranking, there is no indication that it wants to even start. I'm getting good fuel, spark from the coil to the distributor, but no spark to my plug wires (I've tested this)--> This doesn't make sense since it almost fires, spark is somehow getting to the plugs initially. I've checked the ballast (it's fine)--even tried a new one, also a new cap and rotor--no difference. I have a pertronix electronic ignition (Ignitor) kit installed, it's worked great for years. I'm starting to think this may be the problem. I checked the connection from the wires that lead to the ballast, electricity is flowing end to end. Before I go out and buy a new kit, just wondering if there is anything else I need to look for. Thanks!

'68 Dodge Dart
273 2bbl
 
Get a multimeter. Make sure you're getting 12 volts to the ignition system. There is a huge direct wire running the starter. Everything else, including the start relay is running on much smaller wires with many connections. May be some faulty connections.
 
If you have spark at the coil, do you have it at the cap from the coil wire? If you've got nothing coming out of the cap then the problem has to be in the cap or rotor. Make sure the rotor isn't allowing the current(spark) to pass through it &ground out on the distributor shaft. Look for any signs of burning on the bottom as well as the top of the rotor. Espescially in where the rotor fits over the shaft.

Reading your post 1 more time made me think/wonder if its a bad ignition switch or the circuit from the switch. It may be getting good voltage in the starting position but losing it when the key is released to the run position. But I may be confused as to what you're trying to say. Tell us more how/ what method you're using to check the spark.
 
Yes, if you are geting good spark from the hot wire from the coil but not to the plugs, then the problem is in the cap or rotor or whatever is turning the rotor button.

As lonewolf says, describe how you are testing the spark to the distributor cap and then how you are testing out of the plug wires; we need to first get some confidence that the spark from the coil to the distributor is actually good as you say. Also, dry out the inside of the cap with a clean, dry cotton or similar cloth and retry.

The fact that it almost starts on the 1st or 2nd tries but not later tries, may say that the engine is getting flooded, and if this is the case, that issue should be ignored for now. If you smell lots of gas from the carb after trying, it probably is flooding. Do you need help on how to check for proper choke operation? Do you pump the accelrator pedal a lot while trying to start?
 
Try starting/cranking it over at night and look for any sparks under the hood. They will stand out at night in the dark. Looking for a cracked cap or wires and the spark arcing to ground somewhere....

Do you have another cap to swap out and check?
 
Thanks for the input. As stated earlier, I installed a new cap and rotor, still the problem persists. As far as my methodology for testing spark from the coil? I just unplugged the coil wire from the cap while it was still plugged into the coil. I could see and hear spark coming from that coil wire while cranking the engine over--my Dad also got a nasty jolt while holding it too. I didn't mention this in my initial post, but I also installed new plugs (gapped correctly) and wires. I've got my battery charging right now, I need to get some more juice into into it before trying again.
 
Which coil? Some of the Pertronix ignigtors don't use a ballast if using their coil and others use a a funky rotor.
 
Sounds like you do have good spark from the coil based on the 'nasty jolt' comment. (Geez, quit mistreating your old dad! lol) Just FYI, my way of checking is to put a philips scredriver into the end of the spark wire from the coil and lay it with the shaft near the block, with maybe 1/4" gap to the block. It ought be able to jump that gap with a good blue spark when cranking.

You should next try the same technique on any of the wires to the plugs to check if spark is getting to the plugs to verify if you are really geting good spark to the plugs or not; of course, it will fire only 1/8 as often as the spark wire from the coil. I woudl chekc that on at least 2-3 of the plugs wires.

The the cap and rotor is where I would look next if you have good coil spark but no good plug spark. If you have the old rotor, compare it to the new one; look underneath to be sure the indexing tab is in the same orientation. Refer to the above thread on the rotor; there have been many cases of wrong or mismatched rotors and caps. Look for damaged posts inside the cap under the spark towers, and make sure the little springy contact under the center tower is right.

Is the distributor shaft supporting the rotor basically right? It ought to turn one way for about 20-30 degrees and then snap back to its static position when you release it.

Are the plug wires resistor type wires? If you do not know, and you have a multimeter, then measure the resistance in each one end-to-end. They will typically be in the 1k to 5k ohm range. If they get near to 10k, it is time to toss them.

And are the new plugs reistor types? If you have resistor wires and resistor plugs, it ain't gonna work well.

Make sure you wipe down the cap inside and out with a clean dry cloth. If there was carbon or dirt built up on cap inside or out, and the car sets in a moist area for a while, the mositure and dirt/carbon can form a 'carbon track' that will short the spark.

All of the above is probably obvious; just going over basics to gain confidence that you really have good spark or not, before moving on to the next likely problem area.
 
The spark doesn't hurt so much a startle. A single spark ( like when the ignition switch returns from start to run ) or even several weak sparks from the coil wire wont start an engine.
 
I put timing light on to check spark when working alone
 
nm9stheham said:
Sounds like you do have good spark from the coil based on the 'nasty jolt' comment. .
Click to expand...



Sorry disagree. It does not take much of a jolt to "jolt me" but that does not "mean" you have "good spark. Just a few hundred volts can jolt the crap out of me and that is not 'good spark.'
 
Thanks for the help. Yes, the coil is the stock coil. I have heard of using a coil that is made to use with the electronic ignition kit that I have, but the current one has worked just fine for the past 10 years or so. I wonder if I should look into the coil as the possible culprit? How would I know or check to see if it's bad? I have tried the screwdriver method with various plug wires, haven't seen a single spark yet. I'll take a look at the rotor and compare it with the old one. Resistor type plugs and wires? Not sure, I'll check that also.
 
Have you tried getting an extra or new spark plug and pulling one wire off a spark plug, then putting the spare plug in it, holding the bottom electrode to ground, and cranking to look for spark at the plugs.

This way you don't have to unscrew the spark plug. (the lazy/easy way to check for spark at the plug).
 
Why don't we all back up here and do some "actual testing?"

Just EXACTLY how did you test this spark?

"Getting a nasty jolt" is NOT "spark testing."

I ALWAYS use something that I KNOW I can identify with. I use a grounded clip lead with a probe (screwdriver) or test lamp, or a made for purpose test gap.

DO NOT use the factory coil wire, because it's usually a RESISTOR wire. Use a solid core wire, even a piece of low tension wire which you can "carefully" "rig" in the open air to be away from metal.

In fact, if you DO get spark "out of the coil" but 'not at the plugs' it might be just as simple as a bad coil wire. Use your head. Apply a bit of logic. Take a good hard look at the cap and rotor. Are they clean? dry? What have you done to CHECK the coil wire and plug wires? DID you check them? You cannot just stand there and look at them. In this day and age, every hardware, parts, and Sears store on the planet has multimeters at reasonable prices. This is a HUGE change from 20 years ago so there is NO NO excuse why a would be shade tree mechanic cannot acquire and learn to use a multimeter.

You MUST provide good solid battery voltage to the Pertronix and coil during test

This means you must REALIZE the following::

You could have a problem in the cranking circuit. That is, the cranking circuit, the ignition switch, provides the only ignition voltage to the system through what is called the bypass circuit (IGN 2) during cranking. This circuit might have PROBLEM and needs to be checked. YOU DO THIS by checking at the coil + with a voltmeter during cranking BY USING THE KEY to crank the engine

You MUST have within a few tenths of "same as" battery voltage there and certainly not below 10V. You can temporarily jumper a clip lead to coil + from battery

A good spark should be hot, blue, and at least 3/8" and more like 1/2" long. That's inches, not metric.

Even if the cap / rotor "looks" OK, SUSPECT things. Take a GOOD look at that rotor. I've had "interesting" things "happen." I once had a rotor "punch through and did not see it at first. That rotor is normally BLACK and in a DARK garage sometimes you cannot see a CARBON BLACK "punch through UNDER NEATH the rotor contact. ALSO AND PAY ATTENTION One time I ran into an off brand rotor that was built like a GOD DAMMED Jap radio suppressed Colt rotor along-side-my-friend's-sister's-car-that-we-fixed-with-a-hairpin-on-the-side-of-the-road-rotor

THIS THING has a radio suppression resistor inside a trough in a tar encased capsule

3823-1.jpg
 
67Dart273 said:
Sorry disagree. It does not take much of a jolt to "jolt me" but that does not "mean" you have "good spark. Just a few hundred volts can jolt the crap out of me and that is not 'good spark.'
Click to expand...
Well Del, you and I are both making presumptions on the level of 'nasty'. As said by many, a good spark should jump a gap of 1/4" or more and be blue, not wimpy yellow. Getting consistent data with good confidence tests is what counts.

To the OP.....the fact that you don't see good sparks with the screwdriver is good info, but please make sure you are carefully to set the gap from the screwdriver to ground to pretty close to 1/4" inch. It can't jump a gap of 1" reliably. Del's point with the probe is to have a known consistent gap from test point to ground.

Next, please, take the screwdriver (or whatever probe you make) and put it in the end of the spark wire from the coil, set it up with a gap to ground (like the block) of 1/4", and see if you get a completely regular sequence of solid blue sparks as it is cranked. This needs to known. If this is good, then the coil is good, and then you can then focus in the cap and rotor area. If the spark from the coil wire is not good, then you can start working backwards.

(And BTW, I hope you don't mind my saying ..... this all can be done in an orderly sequence and it will save you time and save us all time in helping as we don't have enough high confidence info to work from. These circuits are all a case of 'A' causes 'B' causes 'C' to happen, so the best way to troubleshoot long distance is to do A, then B, then C in order. Guessing all over from A to L to X can't be followed by us.)
 
Lonewolf3165 said:
Reading your post 1 more time made me think/wonder if its a bad ignition switch or the circuit from the switch. It may be getting good voltage in the starting position but losing it when the key is released to the run position.
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I just fixed this problem on my 70 Dart I just bought. The engine would kick and start when cranking, then immediately die when key was released to ON position. Turned out the ignition box was wired for 12v in start position, but no voltage in ON. Jumped it to another pin I tested for 12v in both positions, and it fired right up.
 
Interesting theory, Mac. I'll have to take a look and test it. I've tried pretty much everything I can think of. I even removed the electronic ignition conversion from the distributor to see if it was burned out (apparently, leaving the key in the on position for extended periods of time is bad for it). No difference using points, so I'm at a loss. I'll be back on it on Friday.
 
had this problem with my 68 it was the wiring plug that goes though the firewall had oxidised cleaned it up started up first hit on the key
 
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